Tension Headache (ICD-11: 8A81): Complete Coding and Diagnostic Guide

1. Introduction

Tension-type headache represents the most common type of primary headache in the world population, affecting millions of people across all age groups. It is characterized by episodes of headache typically bilateral in location, with a pressing or tightening quality, mild to moderate intensity, that does not worsen with routine physical activities. Unlike other types of headache, tension-type headache rarely presents associated symptoms such as nausea, vomiting, or excessive sensitivity to light and sound, although pericranial tenderness on palpation may be present.

The clinical importance of this disorder transcends its high prevalence. Although generally considered a benign condition, tension-type headache can cause significant impact on quality of life, work productivity, and emotional well-being of patients, especially when it evolves into chronic forms. Studies demonstrate that tension-type headache is responsible for considerable work absenteeism and reduction in functional capacity in daily activities.

From a public health perspective, tension-type headache represents an important challenge, consuming significant resources in medical consultations, complementary examinations, and treatments. Correct coding using the ICD-11 system is critical for multiple aspects: it enables appropriate epidemiological monitoring, facilitates cost-effectiveness studies, ensures appropriate reimbursement by health systems, aids in planning public health policies, and allows international comparison of clinical data. Furthermore, accurate coding is essential for clinical research, development of therapeutic guidelines, and evaluation of the efficacy of preventive and therapeutic interventions.

2. Correct ICD-11 Code

Code: 8A81
Description: Tension-type headache
Parent category: Headache disorders

ICD-11 defines tension-type headache as a primary headache disorder with high prevalence, in most cases episodic. The attacks present highly variable frequency and duration, being characterized by headache of mild to moderate intensity, without significant associated symptoms, although pericranial tenderness may be present on physical examination.

An important characteristic highlighted in the official definition is that, in a minority of cases, the disorder evolves with increasingly frequent headaches, with possible loss of episodicity and transformation into chronic tension-type headache. This progression represents an additional therapeutic challenge and requires a differentiated approach.

Code 8A81 has three subcategories that allow more detailed specification of the type of tension-type headache, considering mainly the frequency of episodes. This hierarchical structure allows greater diagnostic precision and facilitates monitoring of patient evolution over time. Appropriate classification among the subcategories is fundamental to determine appropriate therapeutic strategies and prognosis.

3. When to Use This Code

Code 8A81 should be used in specific clinical scenarios where the patient presents typical characteristics of tension-type headache. Below, we present detailed practical situations:

Scenario 1: Episodic headache related to occupational stress
A 35-year-old patient presenting with episodes of bilateral headache, with sensation of tightness or pressure, lasting between 2 to 6 hours, occurring 2 to 3 times per week. The pain is of mild to moderate intensity, not completely preventing daily activities, but causing discomfort. The patient reports that headaches arise mainly after days of intense work, improve with rest, and do not present significant nausea, vomiting, or photophobia. Physical examination reveals tenderness on palpation of pericranial muscles.

Scenario 2: Tension-type headache in student during examination period
A 22-year-old student with a history of recurrent headaches for 3 years, characterized by bilateral band-like or helmet-like pain, of moderate intensity, without throbbing. Episodes last from 4 to 12 hours, occur mainly during periods of greater academic demand, do not worsen with mild physical activity such as walking, and the patient is able to continue their activities despite the discomfort. There are no autonomic symptoms, nausea, or visual aura.

Scenario 3: Chronic tension-type headache with muscle tenderness
A 45-year-old patient with a history of practically daily headache for more than 6 months, with bilateral heaviness or tightness pain, mild to moderate intensity, without pulsatile characteristics. The pain does not prevent basic activities, but causes fatigue and irritability. Physical examination demonstrates tender points on palpation in temporal, occipital, and trapezius muscles. There are no focal neurological signs, significant nausea, or autonomic symptoms.

Scenario 4: Infrequent episodic tension-type headache
A 28-year-old patient presenting with isolated headache episodes, occurring less than once per month, with duration of 3 to 8 hours. The pain is described as bilateral pressure, mild intensity, non-pulsatile, without worsening by routine physical activities. The patient does not present significant associated symptoms and is able to maintain normal activities during episodes.

Scenario 5: Tension-type headache with postural component
A 40-year-old office professional presenting with bilateral tightness headaches, mainly in the occipital and cervical region, with moderate intensity, lasting from 4 to 10 hours. Episodes occur 4 to 6 times per month, frequently at the end of the workday. The pain does not present pulsatile characteristics, there is no nausea or vomiting, and the patient reports that inadequate postures seem to trigger episodes.

Scenario 6: Tension-type headache in patient with anxiety
A 32-year-old patient with a diagnosis of anxiety disorder, presenting with frequent bilateral headaches (10 to 15 days per month), with sensation of pressure or heaviness, mild to moderate intensity, lasting from 2 to 8 hours. The pain is non-pulsatile, does not worsen with mild physical activities, and there are no significant autonomic symptoms or nausea. Physical examination reveals pericranial muscle tension.

4. When NOT to Use This Code

It is essential to recognize situations where code 8A81 is not appropriate, avoiding coding errors that may compromise the medical record and appropriate clinical management.

Specific exclusion: New persistent daily headache
When the patient presents with sudden onset of daily and persistent headache, with clear memory of the day it began, and the headache becomes continuous within 24 hours from onset, the specific code for new persistent daily headache should be used, not code 8A81. This distinction is crucial as it represents different clinical entities with distinct prognoses and therapeutic approaches.

Headache with migraine characteristics
Do not use 8A81 when there are typical migraine characteristics, such as unilateral throbbing pain, moderate to severe intensity that prevents daily activities, worsening with routine physical activities, presence of significant nausea/vomiting, concomitant photophobia and phonophobia, or presence of aura. In these cases, the appropriate code is 8A80.

Headache with prominent autonomic symptoms
When the headache is accompanied by prominent ipsilateral autonomic symptoms such as lacrimation, nasal congestion, ptosis, miosis, or restlessness, especially with a pattern of short and intense attacks, the correct code is 8A82 (Trigeminal autonomic cephalalgias), not 8A81.

Secondary headaches
Do not use 8A81 when there is evidence of an identifiable secondary cause, such as recent head trauma, systemic infection, substance use or withdrawal, cerebral structural alterations, or other underlying medical conditions that explain the headache. In these cases, use specific codes for secondary headaches.

Headache with warning signs
Presence of warning signs (red flags) such as sudden and explosive onset, first headache or worst headache of life, change in usual pattern in a patient with previous headache, focal neurological signs, altered level of consciousness, associated fever, or onset after age 50 requires detailed investigation before assigning code 8A81.

5. Step-by-Step Coding Process

Step 1: Assess diagnostic criteria

The first essential step is to confirm that the patient meets the diagnostic criteria for tension-type headache. Perform a detailed history focusing on specific characteristics: pain location (bilateral is typical), pain quality (pressure, tightness, heaviness, non-pulsatile), intensity (mild to moderate, allowing continuation of activities), duration of episodes (minutes to days), frequency, triggering and aggravating factors.

Specifically investigate the absence of features suggesting other diagnoses: inquire about nausea and vomiting (usually absent or mild), photophobia and phonophobia (if present, usually not concurrent), worsening with routine physical activities (should not occur), autonomic symptoms (must be absent), and presence of aura (does not occur in tension-type headache).

Physical examination should include manual palpation of pericranial muscles (temporals, masseter, pterygoids, sternocleidomastoids, splenius, trapezius), documenting presence and location of increased tenderness or trigger points. Perform basic neurological examination to exclude focal signs. Also assess cervical posture and muscle tension points that may contribute to the condition.

Standardized instruments can assist in evaluation: headache diaries to document frequency, intensity, and characteristics of episodes; functional impact scales to assess repercussions on daily activities; and specific questionnaires for tension-type headache when available.

Step 2: Verify specifiers

After confirming the diagnosis of tension-type headache, determine the appropriate subcategory based on episode frequency. The classification considers the number of headache days per month and total duration of the condition, information that should be obtained through detailed history or preferably through headache diaries maintained by the patient for a minimum period of one month.

Classify as infrequent episodic tension-type headache if episodes occur less than once per month on average (fewer than 12 days per year); frequent episodic tension-type headache if they occur between 1 and 14 days per month for at least 3 months (12 to 180 days per year); or chronic tension-type headache if they occur 15 or more days per month for at least 3 months (180 or more days per year).

Also document whether there is pericranial tenderness on palpation, as this finding has therapeutic and prognostic implications. Assess pain intensity using numerical or visual analog scales, recording whether it is mild (allows all activities) or moderate (hinders but does not prevent activities).

Step 3: Differentiate from other codes

Differentiation from 8A80 (Migraine):
Migraine typically presents with unilateral pain (although it can be bilateral), pulsatile or throbbing quality, moderate to severe intensity that prevents daily activities, worsening with routine physical activities such as climbing stairs, and frequently nausea/vomiting with concurrent photophobia and phonophobia. Aura may precede the headache. In contrast, tension-type headache is bilateral, pressing or tightening, mild to moderate, does not worsen with light physical activities, and does not present significant associated symptoms.

Differentiation from 8A82 (Trigeminal autonomic cephalalgias):
Trigeminal autonomic cephalalgias, such as cluster headache, present with attacks of intense unilateral pain, usually orbital or periorbital, lasting 15 to 180 minutes, accompanied by prominent ipsilateral autonomic symptoms (lacrimation, nasal congestion, rhinorrhea, eyelid edema, facial sweating). Attacks frequently occur at specific times and the patient presents with restlessness during the attack. Tension-type headache does not present these characteristics.

Differentiation from 8A83 (Other primary headache disorder):
This category includes primary headaches that do not fit into the main categories. Examples include primary cough headache, primary exertional headache, primary headache associated with sexual activity, hypnic headache, among others. These have specific characteristics related to triggers or temporal pattern that clearly distinguish them from tension-type headache.

Step 4: Necessary documentation

Adequate documentation should include: detailed description of headache characteristics (location, quality, intensity, duration); episode frequency with specification of the number of headache days per month; identified triggering or aggravating factors; associated symptoms present or absent; physical examination findings, especially pericranial palpation; functional impact on daily and occupational activities; previous treatments and therapeutic response; and justification for exclusion of other differential diagnoses.

Also record information about relevant comorbidities, especially anxiety disorders, depression, sleep disorders, or cervical musculoskeletal conditions. Document complementary investigations performed when applicable, although they are generally not necessary in typical cases of tension-type headache.

6. Complete Practical Example

Clinical Case

A 38-year-old female patient, a teacher, seeks medical care reporting recurrent headaches for approximately 2 years, with worsening over the last 6 months. She describes the pain as a sensation of "tight band around the head" or "heaviness in the head," of moderate intensity, bilateral, predominantly frontal and occipital. Episodes typically last 4 to 8 hours, currently occurring approximately 8 to 10 days per month.

The patient reports that headaches arise mainly during the work week, especially during periods of greater academic demand or prolonged meetings. She denies that the pain is throbbing or pulsating. She reports being able to continue working during episodes, although with discomfort and reduced productivity. She denies nausea, vomiting, significant sensitivity to light or sound. There are no visual symptoms preceding the headache. The pain does not worsen when climbing stairs or performing light physical activities.

She reports that headaches improve partially with rest in a quiet environment and occasional use of simple analgesics. She denies recent head trauma, fever, weight loss, or other systemic symptoms. Past history of mild anxiety, without regular medication use. She denies use of preventive headache medications. She works an average of 8 hours daily in front of a computer, with frequently inadequate posture.

On physical examination: patient in good general condition, vital signs normal, neurological examination without focal changes, pupils isochoric and photoreactive, normal fundoscopy, absence of neck stiffness. On palpation of the pericranial muscles, increased bilateral tenderness is evident in the temporal, occipital, and upper trapezius muscles, with the presence of tender points. Cervical range of motion preserved, although with mild discomfort at the extremes of rotation.

Step-by-Step Coding

Criteria analysis:

Location: bilateral (frontal and occipital) - compatible with tension-type headache
Quality: pressure/tightness, not pulsating - typical of tension-type headache
Intensity: moderate, allows continuation of activities - compatible
Duration: 4 to 8 hours per episode - within expected range
Frequency: 8 to 10 days per month for 6 months - characterizes frequent episodic form
Associated symptoms: absent (without significant nausea/vomiting, without concomitant photophobia/phonophobia) - compatible
Worsening by physical activity: absent - compatible
Physical examination: pericranial tenderness present - typical finding

Exclusion of other diagnoses:

Migraine: excluded by absence of pulsating characteristics, absence of significant associated symptoms, absence of worsening by physical activities, constant bilateral location
Autonomic cephalalgias: excluded by absence of autonomic symptoms, duration of episodes, absence of restlessness
Secondary headache: excluded by absence of warning signs, normal neurological examination, clinical history compatible with primary headache

Code chosen: 8A81 - Tension-type headache

Complete justification:

The clinical presentation meets all criteria for tension-type headache: bilateral pain in pressure or tightness, mild to moderate intensity that does not prevent activities, absence of significant nausea/vomiting, absence of concomitant photophobia and phonophobia, absence of worsening by routine physical activities, and presence of pericranial tenderness on physical examination.

The frequency of 8 to 10 days per month for more than 6 months classifies the condition as frequent episodic tension-type headache (subcategory of 8A81), as it occurs between 1 and 14 days per month for at least 3 months. It does not meet criteria for chronic form (which would require 15 or more days per month).

The absence of autonomic symptoms, pulsating characteristics, worsening by physical activities, and the presence of pericranial muscle tenderness are elements that reinforce the diagnosis of tension-type headache and exclude other categories of primary headaches.

Applicable complementary codes:

Additional coding may be considered for anxiety disorder (if clinically significant) and for related cervical musculoskeletal conditions, when present and relevant to the patient's overall management.

7. Related Codes and Differentiation

Within the Same Category

8A80: Migraine

When to use 8A80: Use this code when the patient presents with recurrent headache attacks lasting 4 to 72 hours, characterized by typically unilateral, throbbing pain, moderate to severe intensity, worsening with routine physical activities, and accompanied by nausea and/or photophobia and phonophobia. Aura may precede the headache in some cases.

Main difference vs. 8A81: Migraine presents with more severe intensity that typically prevents daily activities, throbbing quality, worsening with physical activity (the patient prefers to rest), and prominent associated symptoms (nausea/vomiting, photophobia and phonophobia occurring together). Tension-type headache has mild to moderate intensity allowing continuation of activities, pressing or tightening quality, does not worsen with mild physical activities, and does not present significant associated symptoms.

8A82: Trigeminal autonomic cephalalgias

When to use 8A82: This code is appropriate for headaches characterized by attacks of intense unilateral pain, usually orbital, supraorbital or temporal, lasting 15 minutes to 3 hours, accompanied by prominent ipsilateral autonomic symptoms such as lacrimation, nasal congestion, rhinorrhea, palpebral edema, facial sweating, miosis, ptosis. Includes cluster headache, paroxysmal hemicrania, and others.

Main difference vs. 8A81: Trigeminal autonomic cephalalgias present with intense unilateral pain with prominent ipsilateral autonomic symptoms, attacks of specific and relatively short duration, often at predictable times, and the patient exhibits restlessness during attacks. Tension-type headache is bilateral, without autonomic symptoms, with more variable duration (hours to days), and the patient does not exhibit restlessness.

8A83: Other primary headache disorder

When to use 8A83: Use for primary headaches that do not fit into the main categories. Examples include primary cough headache (triggered by cough, sneeze or Valsalva maneuver), primary exercise headache (triggered only during or after physical exercise), primary headache associated with sexual activity, hypnic headache (awakens the patient from sleep), primary thunderclap headache, among others.

Main difference vs. 8A81: These headaches have specific characteristics related to particular triggers or unique temporal patterns that clearly distinguish them. Tension-type headache has no specific relationship with these particular triggers and presents a temporal pattern more related to stress, muscle tension or postural factors.

Differential Diagnoses

Medication overuse headache: Should be considered when there is regular use of analgesics or specific headache medications for 10 or more days per month for more than 3 months. In these cases, the headache may have characteristics of tension-type headache, but the appropriate code would be for headache secondary to medication overuse.

Cervicogenic headache: Characterized by unilateral pain that begins in the cervical region and radiates to the frontal region, with evidence of cervical origin (reduced range of motion, pain provocation by pressure on cervical structures). Although there may be overlap with tension-type headache, especially when there is a muscular component, cervicogenic headache has a specific code.

Temporomandibular disorders: May cause bilateral headache in the temporal region, but there is usually pain or dysfunction in the temporomandibular joint, pain with mastication, or limited mouth opening. When headache is secondary to temporomandibular disorder, it should be coded as such.

8. Differences with ICD-10

In ICD-10, tension-type headache was coded as G44.2, with subdivisions: G44.20 (unspecified tension-type headache), G44.21 (episodic tension-type headache), and G44.22 (chronic tension-type headache). The structure was simpler and less detailed.

ICD-11 introduces significant changes in coding: the main code becomes 8A81, with a more elaborate hierarchical structure that allows more precise specification of episode frequency. ICD-11 clearly distinguishes between infrequent episodic tension-type headache, frequent episodic, and chronic, based on more specific frequency criteria aligned with the International Classification of Headache Disorders.

Another important change is the emphasis on the presence or absence of pericranial tenderness, which in ICD-11 is recognized as a relevant characteristic with clinical implications. ICD-10 did not specify this aspect as clearly.

The definition in ICD-11 also explicitly highlights the potential evolution of the disorder, mentioning that in a minority of cases there is progression with increasingly frequent headaches and loss of episodicity. This evolutionary perspective was not as emphasized in ICD-10.

From a practical standpoint, the transition to ICD-11 requires familiarization with the new code structure and more specific criteria for frequency classification. Health information systems need to be updated to accommodate the more complex hierarchical structure. For purposes of comparing historical epidemiological data, it is important to maintain correspondence tables between ICD-10 and ICD-11, although the correspondence is not always direct due to conceptual differences.

9. Frequently Asked Questions

How is tension-type headache diagnosed?

The diagnosis of tension-type headache is essentially clinical, based on detailed history and physical examination. The physician investigates pain characteristics (location, quality, intensity, duration), frequency of episodes, triggering factors, associated symptoms, and functional impact. Physical examination includes neurological evaluation and palpation of pericranial muscles. There are no specific laboratory or imaging tests to diagnose tension-type headache; these are reserved for situations where there is suspicion of secondary causes or presence of warning signs. Headache diaries maintained by the patient for a period of 4 to 8 weeks are valuable tools for characterizing the pattern and frequency of episodes.

Is treatment available in public health systems?

Yes, treatment for tension-type headache is generally available in public health systems. Management includes non-pharmacological measures (relaxation techniques, stress management, postural correction, physical therapy) and pharmacological approaches. For acute treatment of episodes, simple analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs are commonly used and generally available. For cases of frequent or chronic tension-type headache, preventive medications such as tricyclic antidepressants in low doses may be necessary. The availability of complementary approaches such as physical therapy, acupuncture, or cognitive-behavioral therapy may vary among different health systems and regions.

How long does treatment last?

The duration of treatment varies according to the form of tension-type headache and individual response. For infrequent episodic tension-type headache, treatment may be symptomatic only during episodes, without need for continuous preventive therapy. In cases of frequent episodic tension-type headache, preventive measures are frequently recommended for a minimum period of 3 to 6 months, with subsequent reassessment. For chronic tension-type headache, preventive treatment is generally maintained for 6 to 12 months or longer, with gradual reduction after achieving adequate control. Non-pharmacological approaches, especially those related to lifestyle, stress management, and ergonomics, should be maintained long-term. Regular medical follow-up is important for therapeutic adjustment as needed.

Can this code be used in medical certificates?

Yes, code 8A81 can and should be used in medical certificates when appropriate. Tension-type headache, especially in its more frequent or chronic forms, can cause temporary incapacity for work or usual activities. The certificate should specify the ICD-11 code (8A81) and the period of leave needed, based on symptom intensity and functional impact. It is important that the physician adequately document the justification for leave, considering that tension-type headache typically has mild to moderate intensity. Prolonged or frequent absences should be well-founded and may require investigation of contributing or complicating factors, such as psychiatric comorbidities, excessive medication use, or transformation to chronic form.

Can tension-type headache evolve into migraine?

Tension-type headache and migraine are distinct disorders with different pathophysiologies. There is no evidence that tension-type headache transforms into migraine. However, it is possible for the same patient to present both types of headache at different times, a situation called coexisting headaches. Some patients may have difficulty distinguishing between the two types when they have both. It is also important to recognize that excessive use of analgesics to treat frequent tension-type headache can lead to medication overuse headache, which may present with mixed characteristics. Careful evaluation of the characteristics of each headache episode is fundamental for appropriate diagnosis and treatment.

What are the main triggering factors of tension-type headache?

The most common triggering factors include emotional or psychological stress, sustained muscle tension (especially in the cervical region and shoulders), prolonged inadequate postures (common in office work), sleep deprivation or irregularity, fatigue, prolonged fasting, and environmental factors such as noisy environments or inadequate lighting. Some patients identify relationships with menstrual periods, climate changes, or consumption of certain foods, although these associations are less consistent than in migraine. Identifying and modifying individual triggering factors is an important component of management, often through headache diaries that allow recognition of specific patterns for each patient.

Is tension-type headache related to psychological problems?

There is a significant association between tension-type headache, especially chronic forms, and psychological disorders such as anxiety and depression. This relationship is bidirectional: psychological disorders can increase the frequency and intensity of headaches, while chronic headache can contribute to the development or worsening of anxious and depressive symptoms. Chronic stress is recognized as an important factor both in triggering and in chronification of tension-type headache. Therefore, psychological evaluation is an important part of the diagnostic approach, and treatment frequently includes strategies for managing stress, anxiety, or depression when present. Approaches such as cognitive-behavioral therapy, relaxation techniques, and biofeedback have demonstrated efficacy in treating tension-type headache.

Is it necessary to perform brain imaging tests?

In most cases of tension-type headache with typical presentation and normal neurological examination, brain imaging tests are not necessary. The diagnosis is clinical and complementary tests generally do not add relevant information. However, imaging tests are indicated when there are warning signs (red flags) such as sudden and severe onset, significant change in the pattern of previous headache, onset after age 50, focal neurological signs, altered consciousness, systemic symptoms such as fever and weight loss, or when neurological examination reveals abnormalities. The decision regarding imaging tests should be individualized, considering the complete clinical picture and medical judgment. Performing unnecessary tests can generate avoidable costs and patient anxiety.

Conclusion

Tension-type headache, coded as 8A81 in ICD-11, represents the most common type of primary headache, characterized by episodes of bilateral pressing or tightening pain, mild to moderate intensity, without significant associated symptoms. Appropriate coding requires understanding of specific clinical characteristics, diagnostic criteria, and careful differentiation from other types of primary and secondary headache. The hierarchical structure of ICD-11 allows more precise specification of episode frequency, facilitating therapeutic planning and evolutionary follow-up. Correct recognition and appropriate coding of tension-type headache are fundamental to ensure adequate clinical management, accurate epidemiological recording, and appropriate allocation of health resources.

External References

This article was prepared based on reliable scientific sources:

References verified on 2026-02-04

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