Tension Headache: Labs, Diagnosis, and Next Steps

What Exactly Is a Tension-Type Headache?

Tension-type headache is a bilateral, pressing or tightening pain of mild to moderate intensity that does not worsen with routine physical activity like walking or climbing stairs. The International Headache Society's ICHD-3 classification distinguishes it from migraine by the absence of nausea, vomiting, and combined photophobia plus phonophobia [3].

TTH is the single most prevalent neurological disorder on the planet. The Global Burden of Disease study estimated that TTH affected 1.89 billion people in a single year, placing it ahead of migraine in raw prevalence [2]. Despite these numbers, it receives a fraction of the research funding migraine does. A 2023 review in Nature Reviews Disease Primers noted that "tension-type headache remains the most neglected and least studied of the primary headache disorders, despite being the most prevalent" [6]. That neglect has practical consequences: many patients never receive a formal diagnosis, and physicians often skip the structured evaluation that separates TTH from headaches caused by medication overuse, cervical pathology, or intracranial disease [5].

The disorder exists on a spectrum. Infrequent episodic TTH (fewer than 12 days per year) rarely needs medical attention. Frequent episodic TTH (1 to 14 days per month) begins to impair quality of life. Chronic TTH (15 or more days per month for 3 months or longer) produces disability comparable to migraine, with a European study finding mean annual costs of €596 per chronic TTH patient in lost productivity alone [7].

Why Tension Headaches Happen

The name "tension headache" implies that muscle tension is the cause. That explanation is incomplete. Current evidence points to a combination of peripheral myofascial sensitivity and altered central pain processing, with the balance shifting toward central mechanisms as headache frequency increases [6].

In episodic TTH, pericranial muscles (temporalis, frontalis, trapezius, sternocleidomastoid) show increased tenderness on palpation. A meta-analysis of 14 studies found that pericranial tenderness scores were significantly elevated in TTH patients compared to controls (standardized mean difference 1.07 to 95% CI 0.81 to 1.33) [8]. This peripheral nociceptive input appears to be the primary driver of infrequent attacks.

Chronic TTH involves a different mechanism. Prolonged peripheral nociceptive input can sensitize second-order neurons in the trigeminal nucleus caudalis, lowering the threshold for pain perception. Dr. Lars Bendtsen, who led the European Federation of Neurological Societies (EFNS) guideline panel, described this process: "Central sensitization is the most significant finding in chronic tension-type headache and is likely caused by prolonged nociceptive input from pericranial myofascial tissues" [4].

Common triggers that feed this cycle include sleep deprivation, psychological stress, sustained awkward posture (particularly forward head position during screen use), irregular meal timing, dehydration, and caffeine withdrawal. None of these triggers alone causes TTH, but in a susceptible individual, they lower the activation threshold for an attack.

How Doctors Diagnose Tension Headache

Diagnosis rests entirely on clinical history and physical examination. There is no blood test, imaging finding, or biomarker that confirms TTH. The ICHD-3 diagnostic criteria require all of the following for episodic TTH: bilateral location, pressing or tightening (non-pulsating) quality, mild to moderate intensity, and no aggravation by routine physical activity [3]. The headache must also lack nausea/vomiting and cannot have both photophobia and phonophobia simultaneously (one alone is permitted).

A structured headache history is the most valuable diagnostic tool. The clinician should ask about onset pattern, location, quality, intensity on a 0-to-10 scale, duration (TTH episodes typically last 30 minutes to 7 days), associated symptoms, frequency, medication use, and impact on daily function. A headache diary kept for at least 4 weeks provides more reliable data than patient recall, which tends to overestimate frequency in some patients and underestimate it in others [5].

Physical examination focuses on palpation of pericranial muscles and a basic neurological screen. The American Academy of Family Physicians recommends manual palpation of the frontalis, temporalis, masseter, pterygoid, sternocleidomastoid, splenius, and trapezius muscles bilaterally, using small rotating movements with the second and third fingers for 4 to 5 seconds at each site [9]. Increased tenderness supports the diagnosis. A normal neurological examination (intact cranial nerves, normal strength and reflexes, no papilledema) confirms the primary nature of the headache.

Lab Tests: What Is Actually Needed?

For a patient whose history and exam fit classic TTH with no red flags, no laboratory testing is indicated. The EFNS guideline explicitly states that "no investigation is needed for the diagnosis of TTH" [4]. Ordering routine bloodwork in this scenario adds cost without clinical benefit.

Lab tests become appropriate when the clinical picture raises suspicion of a secondary headache or a comorbid condition contributing to headache frequency. Specific scenarios and their corresponding tests include:

Thyroid dysfunction. Hypothyroidism can produce chronic daily headache that mimics TTH. A TSH level is warranted when the patient reports fatigue, weight gain, cold intolerance, or constipation alongside headache. A population-based Norwegian study (N=51,383) found that individuals with TSH above 5.0 mIU/L had a 21% higher prevalence of chronic headache compared to euthyroid controls [10].

Anemia. Severe iron-deficiency anemia (hemoglobin <10 g/dL) can cause or worsen headache. A complete blood count with ferritin is reasonable when the patient appears pale, reports dyspnea on exertion, or has a history of heavy menstrual bleeding.

Inflammatory markers. In patients over age 50 with new-onset headache, an erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) help screen for giant cell arteritis. The American College of Rheumatology recommends measuring both, as their combined sensitivity exceeds 97% [11].

Metabolic panel. Chronic kidney disease and electrolyte imbalances (particularly hyponatremia) can present with persistent headache. A basic metabolic panel is warranted if the patient has risk factors such as diabetes, hypertension, or chronic NSAID use.

Medication overuse screening. This is a history-based assessment, not a lab test, but it is the single most important "investigation" in any patient with chronic daily headache. Using simple analgesics on 15 or more days per month, or triptans/opioids/combination analgesics on 10 or more days per month, meets the ICHD-3 criteria for medication-overuse headache [3]. A 2004 population study estimated that 1% to 2% of the general population has medication-overuse headache, and these patients are frequently misdiagnosed with chronic TTH [12].

When Imaging Is Warranted

Brain MRI or CT is not part of the routine TTH workup. The American College of Radiology Appropriateness Criteria rates neuroimaging as "usually not appropriate" for patients meeting TTH criteria with a normal neurological examination [13].

Imaging becomes necessary when any of the following red flags are present. A useful mnemonic from a 2019 BMJ clinical review is SNNOOP10: Systemic symptoms (fever, weight loss), Neoplasm history, Neurologic deficit, Onset that is sudden or thunderclap, Older age (>50 years with new headache), Pattern change (headache that is progressively worsening), Positional component, Precipitated by Valsalva, Papilledema, and Pregnancy/postpartum [5]. Any single SNNOOP10 flag should prompt imaging, typically MRI with and without gadolinium contrast.

A large retrospective study of 1,876 patients who presented to a headache clinic with "tension headache" found that 2.7% had a secondary cause identified on MRI, with the majority being incidental findings of low clinical significance [14]. This low yield supports the guideline recommendation against routine imaging but confirms the value of targeted imaging when red flags are present.

First-Line Treatments That Work

Acute treatment of episodic TTH relies on simple analgesics. The EFNS guideline, based on 37 randomized controlled trials, recommends ibuprofen 400 mg as the top first-line option. A single dose produced a pain-free response at 2 hours in 44.2% of patients vs. 27.5% for placebo (NNT = 6) [4]. Aspirin 1 to 000 mg and acetaminophen 1 to 000 mg are alternatives, though aspirin carries more gastrointestinal risk and acetaminophen showed slightly lower efficacy in head-to-head trials [4].

Key prescribing points that prevent complications:

Limit acute analgesic use to 2 days per week on average. Exceeding this threshold over 3 months risks medication-overuse headache, which converts episodic TTH into a chronic daily pattern that is harder to treat. Combination analgesics containing caffeine (e.g., acetaminophen/aspirin/caffeine) are more effective than single agents but carry a higher risk of overuse, so they should be reserved for patients whose attacks do not respond to simple analgesics alone.

Avoid opioids entirely. No controlled trial supports opioid use for TTH, and the risk of dependence and medication-overuse headache makes them inappropriate at any step of the treatment ladder [4].

Preventive Therapy for Chronic Tension Headache

When TTH occurs on 15 or more days per month, preventive medication becomes the priority. Amitriptyline is the only drug with strong evidence from multiple randomized controlled trials. The EFNS guideline recommends starting at 10 to 25 mg at bedtime and titrating by 10 to 25 mg weekly to a target of 25 to 75 mg [4]. A Cochrane review of 8 trials (N=601) confirmed that amitriptyline reduced headache frequency by 4.8 days per month compared to placebo [15]. The drug's analgesic effect is independent of its antidepressant action and appears at lower doses.

Second-line options supported by smaller trials include mirtazapine (15 to 30 mg nightly) and venlafaxine (150 mg daily). Mirtazapine showed benefit in a single RCT (N=94) with a 34% reduction in headache days versus placebo at 8 weeks [16]. Venlafaxine was effective in a crossover trial but has a more challenging side-effect profile.

Non-pharmacologic approaches have growing evidence. A randomized trial (N=250) published in BMJ compared acupuncture plus usual care versus usual care alone and found that the acupuncture group experienced 6.2 fewer headache days per month at 12 months [17]. Physical therapy targeting cervical and pericranial muscles reduced headache frequency by approximately 50% in a controlled study of 84 patients with chronic TTH [18]. Cognitive behavioral therapy (CBT) specifically adapted for headache management produced comparable reductions to amitriptyline in a head-to-head trial, with the combination of CBT plus amitriptyline outperforming either alone [19].

Building a Step-by-Step Next-Steps Plan

A practical action sequence for someone experiencing recurrent tension headaches:

Step 1: Track. Keep a headache diary for at least 28 days. Record date, duration, intensity (0 to 10), location, associated symptoms, medications taken, and potential triggers. Free apps exist, but a simple spreadsheet works equally well.

Step 2: Count. After 28 days, calculate headache days per month and analgesic days per month. If headache days are 15 or more, you may have chronic TTH. If analgesic days are 10 or more, medication-overuse headache is a concern.

Step 3: See a clinician. Bring the diary. The clinician will apply ICHD-3 criteria, perform a neurological exam, and determine whether any lab tests or imaging are indicated based on your specific presentation.

Step 4: Address modifiable triggers. Sleep 7 to 8 hours on a consistent schedule. Limit caffeine to 200 mg or less per day and keep intake consistent. Correct forward-head posture during screen work. Add 150 minutes per week of moderate aerobic exercise, which a meta-analysis of 6 RCTs associated with a 0.6-point reduction in headache intensity on a 10-point scale [20].

Step 5: Use acute medication correctly. Take ibuprofen 400 mg or acetaminophen 1 to 000 mg at headache onset. Do not wait for pain to become severe. Limit use to 2 days per week.

Step 6: Discuss prevention if needed. If chronic TTH is diagnosed, ask about amitriptyline. Expect 4 to 6 weeks before full benefit. Combine with physical therapy or CBT for best outcomes.

The threshold for specialist referral: headache that does not respond to two preventive medications tried at adequate dose for adequate duration (at least 8 weeks each), headache with atypical features, or headache accompanied by any SNNOOP10 red flag [5].