Headache – and how to avoid one as a doctor

By Dr Lou Wiblin, Consultant Neurologist, Middlesbrough

Headache is incredibly common. It is thought that almost 5% of the world’s population has headache 15 days out of every month. In UK A&E’s, 2% of patients present with headache.

Headache is a vast topic but can be broadly divided into two groups by time frame and by cause. Headache can be an acute or a new problem (this tends to make up the majority of patients attending A&E) or chronic; a problem which is recurrent. The latter tend to attend their GP or see neurologists for advice on managing their headaches.  This piece will focus on acute headaches and how to safely assess and manage these patients.

The other important way of dividing headaches is into primary and secondary forms. Primary headaches are disorders which in themselves cause headache. The most common form is migraine; around 1 in 7 people have recurrent migraine. Secondary headache is caused by another underlying problem. These are the headaches which keep medics awake (and headachy!) at night. It is important to pick up clues that might point to a disease process causing a headache and these are known as the ‘red flags’ (see figure 1). As these flags are important to understand, I have given 5 worked examples of red flags of secondary headaches below. Afterwards we will go through the characteristics of the more common primary headaches.

Screenshot 2019-10-10 at 21.27.34
Figure 1: Common red flags of secondary headache disorders

The system often used in practice is the ‘rule out subarachnoid haemorrhage (SAH)’. This takes patients admitted with headache, carries out a CT to rule out obvious lesions, an LP will then rule out SAH or meningitis. The patient is discharged with a non-diagnosis of ‘no SAH or meningitis found’. Hopefully after reading, you will have more of a feeling for screening for red flags which need ruling out, then which elements of the history and examination you need to tease out to give a diagnosis. Better for the patient and more satisfying for the doctor!

Case 1: “It felt like a brick”

34-year-old man presents to A&E after collapsing at work with a headache like “being smacked with a brick at the back of my head”. He rarely has headache and tells you this is the worst he has ever had. The headache was maximal at the onset and has eased slightly but is still painful. He looks fairly well lying still but insists the lights are kept low as they hurt his eyes. When he is examined, the registrar notes that he is ‘Kernig positive’.

SAH CT scan
Figure 2: Unenhanced CT head, for case 1

He receives an unenhanced CT scan of the head (figure 2).

What next?

Discussion: In any patient who describes a sudden onset, severe headache, subarachnoid haemorrhage should be considered. In this case the patient rarely experiences headaches so it is straightforward that there is an acute problem. He is also clear that the onset was very sudden; the description of being hit on the head is typical and very helpful. When taking a history of a headache, it is important to be clear if it truly is ‘sudden-onset’ or not. Sudden builds to its worst over seconds as opposed to minutes or hours.

When examined, patients with an SAH may have reduced conscious level though can actually appear really quite well. Blood producing meningeal irritation produces signs such as a stiff neck and photophobia. The Kernig sign suggests meningeal irritation from hamstring spasm so that the knee cannot be passively extended (limited by stiffness or pain) by the examiner when hip and knee positioned to 90 degrees. Clinical meningism signs are helpful if found and have a high specificity but a very low sensitivity of 5%, so their absence should not reassure you too much!

CTH which should be done as soon as safely possible in anyone with suspected SAH. Figure 2 shows a classic ‘star sign’ of subarachnoid blood lying within the basal cisterns. This is a fairly florid example. CT scans in headache have some key advantages; they are quick, easier to report by radiologists and are very helpful in detecting blood and large lesions (like tumours). In this example there was blood present clearly in the scan so a call to a friendly neurosurgeon is the next step. What if the scan is normal?

If SAH is being considered, a normal CTH is insufficient to rule this out and a lumbar puncture (LP) will be required. The LP should be performed 12 hours after the onset of headache to avoid a false negative. The CSF should be protected from light using a light-opaque container on its trip to the lab (beware the envelope with a window!) to avoid blood by-product breakdown. Oxyhaemoglobin should appear in the CSF 4 to 10 hours after a bleed, hence the delay. Products of blood breakdown can be detected 3 (70%) or even 4 weeks (40%) after a bleed though post 12hrs and within 2 weeks is the usual window of detection.

Special tips for SAH:

  • Always clarify time-frame of onset. When was pain maximal?
  • Beware ‘herald bleeds’-previous sudden onset headaches which can ‘herald’ a bigger and more devastating bleed
  • Check blood pressure! May need to be controlled
  • Any anticoagulant therapy?
  • People may appear deceptively well

Case 2: “It’s bright in here!”

A 23-year-old woman presents to hospital with a headache which has evolved over days. She describes neck stiffness, sensitivity to light and has vomited.  Whilst in the department she is found to have a temperature of 38.6 degrees Celsius. There is no focal weakness, no confusion. She has no rash. There is difficulty visualising her fundi due to her photophobia and the A&E SHO wonders if the margins are blurred.

What next?

Discussion: This is a common emergency presentation. The priority in someone suspected of having bacterial meningitis is to assess safety for lumbar puncture (which is a diagnostic procedure) and to ensure antibiotic treatment is not delayed if tests are taking time to organise.  The red flags here are that she is systemically unwell with fever and meningism and may have focal neurology with blurred optic discs.

If there are focal signs such as weakness, cranial nerve palsies, suspicion of raised intracranial pressure (such as suspicion of blurred optic discs) a CT head scan should be carried out prior to lumbar puncture. Similarly, a scan is mandatory if there is reduced consciousness level, immunocompromise or if the patient has had a seizure. If this will delay treatment, it is common to carry out blood cultures, give antibiotics (usually a broad-spectrum cephalosporin) with ampicillin if over 60years or history of immunocompromise. Antibiotic formularies exist in all trusts and will have alternatives if patients have penicillin allergies. It’s wise to know where to find the formulary before your first on-call shift!

If safe to do, an LP should be carried out as quickly as possible; the culture results should inform any change in the antibiotic treatment. It is now part of best practice to give corticosteroids when antibiotic treatment has commenced (with or within 15mins of first dose) as this reduces the risk of hearing loss as a result of meningitis. Patients can be extremely sick and frequently require extra support and monitoring on the ITU.

The most common organisms causing meningitis in the UK are Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b (Hib).  There are 0.7 cases of bacterial meningitis in the UK per 100,000 people per year compared with around 20-30 per 100,000 in African nations where vaccination is less extensive. *(BMJ Best Evidence Meningitis, Sept 2018).

Initial results in a lumbar puncture in bacterial meningitis may show cloudy or turbid fluid (as opposed to ‘crystal clear- ‘gin-clear was popular in the 1990s!). White cells are raised, often hugely, predominantly neutrophils. The glucose levels in the CSF are reduced relative to the serum and pressure in the CSF using a manometer is frequently high (see figure 3).  Gram stains may be delayed by hours or several days but can inform antibiotic choice.

Screenshot 2019-10-10 at 21.28.55
Figure 3: reference ranges for CSF in health, bacterial and viral meningitis

Special tips for bacterial meningitis:

  • Always treat if there will be any delay in investigations; do blood cultures first
  • Corticosteroids can reduce morbidity and should be given with antibiotics
  • CTH is needed pre-LP if there is focal neurology, signs of raised ICP, seizure or reduced GCS
  • Support from your seniors, microbiology and ITU teams important for best outcomes in meningitis

Case 3: “She’s not herself…”

A 58-year-old GP is reviewed in the medical admission unit. She has had headaches for a few days. She is unable to answer specific questions about the onset of her headache nor discuss any previous medical or drug history. She is orientated to time, place and person and appears superficially normal during a casual conversation. Her husband brought her to the unit when she was unable to use her computer nor use a cash point (ATM for our American friends). She has a mild pyrexia of 38.2 degrees Celsius, no focal weakness but mild dysphasia. Soon after her initial clerking she has a generalised convulsive seizure.

What next?

Discussion: This case demonstrates some differences between the presentation in example 2 of meningitis and encephalitis. She has clear red flags of confusion, fever and seizures. Although meningitis patients may be confused, particularly if conscious levels are reduced they are often lucid though unwell, with severe headache and meningism. Encephalitis, as it is infection of the brain itself rather than the meninges produces confusion which can be subtle or dismissed. Clues to the diagnosis are early fever and headache, with progression to behavioural changes or even psychosis then focal neurology and seizures. Remember that encephalitis often has a degree of meningism too (meningoencephalitis).

It is important to start treatment as possible if encephalitis is suspected. The most common cause is HSV (herpes simplex type 1) and the treatment is intravenous acyclovir which should be continued for 14 days (guidelines now also suggest repeating LP if the CSF viral PCR is positive to check the virus has cleared after course of treatment).  As she has had a seizure, a CTH to exclude space occupying lesion is required before an LP but CT is unlikely to provide evidence of encephalitis. MRI is good for picking up changes in soft tissue such as inflammation and oedema and MRI has a range of sequences to better examine the brain. There is also no ionising radiation. The disadvantages of MRI are that scans take longer (an issue if patients are agitated, confused or unwell), are noisy and MRI scans are more difficult to obtain urgently.

This patient received IV acyclovir immediately and an LP was done after a normal CTH. This showed 400 white cells (all lymphocytes), 0.7g of protein and a mildly raised opening pressure of 26cmCSF (see figure 3) with PCR positive for HSV 1 following after several days.

The next day she had improved and seemed more appropriate in speech and cognition and the pyrexia had settled. An MRI scan was carried out and showed increased signal in the right temporal lobe (see fig 4).

The patient improved to the point of living an independent life but was unable to return to her work as a GP due to memory problems; common after HSV encephalitis as it tends to target the temporal lobes.

Figure 4: MRI brain showing enhancement in the right temporal lobe (Radiopaedia)

Special tips for encephalitis:

  • If encephalitis is being considered, you should probably have already given acyclovir; delays in treatment can affect survival and functional recovery
  • CT excludes lesions but MRI needed to show evidence of oedema and enhancement due to viral infection-usually in the temporal lobes
  • It can be really helpful to daily assess cognition and document this so recovery and improvement can be objectively tracked-the MOCA is a good tool. Entry of ‘seems better’ in the notes isn’t that helpful!

Case 4: “Up and about”

A 58-year-old man attends the MAU clinic. He has had gradually worsening headache over 2 months which is not pounding in nature. It has not affected her vision and there is no photophobia. The headache is fairly bothersome first thing in the morning but he has not previously been to a doctor as she remarks that it improves once he gets out of bed and is “up and about”. Although he has had no nausea he has vomited unexpectedly a couple of times in the night over the past couple of weeks. The reason he come to clinic today is because the headache is now fairly severe when he lies down and his arm has felt a little weak for the past few days. When you examine him, the main finding is that his left arm is globally weak compared to the right.

What now?

Discussion: This patient has had headache for some time but has not presented as she did not find it especially severe. However, there are clear red flags to find within his account of himself. Headache which is more severe lying flat or is worst first thing in the morning then eased once upright is suggestive of raised intracranial pressure. The majority of patients with headache either find posture makes no difference or find some relief lying down. Other signs of raised ICP include worse pain on coughing, sneezing or straining (but most people with any sort of headache do tend to find this…I do!).

Other points of concern for this chap is the fact his headache has not made him feel nauseated but he has unexpectedly vomited a couple of times. Migraine can produce vomiting but usually there is nausea. Most frequently there is a lot of nausea with rare but expected vomiting. The story he relates again suggests raised ICP.

Finally, the chief reason he has sought advice is because he has some weakness of the left arm.  This is a focal neurological sign. This is a red flag and requires imaging of the head as a priority to exclude a focal lesion. In this case an MRI scan showed a malignant tumour in the right temporoparietal lobe (an aggressive tumour called a glioblastoma multiforme-fig 5).

Figure 5: Glioblastoma in the temporal lobe

This explains the raised ICP symptoms and weakness of the left arm. This gentleman’s scan would need discussing urgently with the oncall neurosurgeon and oncology team and would likely need some high dose corticosteroid to reduce the swelling and oedema around the mass. This might have some short-term benefit for his headache and focal neurology.

Special tips for raised ICP symptoms:

  • Headache suggestive of raised ICP is worse lying flat, first thing in the morning, on Valsalva (coughing or straining on the loo).
  • Always look for focal neurology including visual fields and fundoscopy.
  • A CT should be done in the first instance if MRI will produce a delay. CT would have demonstrated the lesion above (though not the detail an MRI provides.

Case 5: “Like magic!”

A 75-year-old woman attends the emergency clinic. She has had a right-sided headache for three months but put it down to migraine which she had in her 20s. Unlike her past migraine, she has no nausea, the pain is not pounding and she gets no relief by lying down in the dark. In fact, when she lays the right side of her head on the pillow it is very tender. She has lost some weight as she feels generally unwell and chewing seems to worsen her headache. When you examine her, her scalp is tender to touch on the right and you notice her hair is uncombed over that area.

What now?

Discussion:  In someone over 50 with a headache that produces scalp tenderness, weight-loss and pain on chewing, you must consider giant cell arteritis (so important they named it twice-otherwise known as temporal arteritis). This is a form of vasculitis or inflammation of blood vessels and it can cause irreversible blindness if not detected and treated promptly.

Key things to ask about are whether the headache involves the temples or the eye, is there tenderness in the scalp (note unwillingness to comb hair or visit a hairdresser as a result) and jaw claudication-pain in the jaw when chewing and any visual loss. When examining, feel for pulses in the temporal arteries – GCA can thicken the arteries but leaves them pulseless (figure 6).

Figure 6: Thickened superficial temporal artery in a patient with GCA

Any patient with these symptoms needs an ESR level. If above 50mm/hr GCA is likely. Patients then need referral for a biopsy of the artery but must be treated in the meantime to avoid visual loss; 60mg prednisolone daily. A biopsy should not be affected by this for 72hrs.

24hrs after starting steroids, the patient had resolution of her pain, “like magic!”. The rapid response to treatment is characteristic of GCA.

Special tips for scalp/eye pain

  • ESR is vital in patients over 50 if any suggestion of temple/eye pain or visual loss. Steroid treatment must be provided same day
  • Sounds obvious, but examine the eye itself. Beware the red eye of glaucoma producing headache-the patient needs an ophthalmologist urgently in that case!

The primary headache disorders

Seems strange to end with the primary headache disorders, but in clinical practice you usually rule out any red flags or clues to a secondary headache first. Provided these are absent or excluded then history and examination can be carried out to give a positive diagnosis of primary headache disorders. There are many types but below are some key examples of common primary headaches

Migraine example: A 19-year-old woman presents with recurrent severe headache and visual disturbance. She describes having visual phenomena like ‘zig-zag lights’, followed by vomiting. Shortly thereafter a pounding headache would result, requiring her to lie down, preferably in low light and silence for comfort until it passes off in a couple of hours.

This is a classical description of migraine with fortification spectra (see figure 7). This was drawn by Dr Airy a 19th century doctor who suffered from migraine. He also described scotoma or gaps in the vision which migraine patients describe. Other clues to migraine are nausea and vomiting, photo and phonophobia (dislike of light and noise) and wanting to lie still. It is more common in women. Aura isn’t always present. People describe feeling ‘washed-out’ afterward.

Cluster headache example: a 26-year-old man presents with headaches which have developed in the past month. He looks exhausted and worried. He tells you when they come on he falls out of bed, they are so severe and he walks around the garden at night holding his head until it goes in around half an hour. It’s happening every night. His girlfriend shows you a mobile phone photo of his face when he has the pain. You notice his left eye looks puffy and his left nostril is running. Examining him now you find nothing. He tells you he hasn’t slept a night through for weeks.

Cluster headache is the most common of the catchily-named trigeminal autonomic cephalgias. Their calling card is autonomic symptoms which is usually locked to one side. They produce agonising pain, usually around or behind an eye. The autonomic features can be watering of that eye, redness, construction of the pupil, stuffiness or running of the nostril on that side or even ptosis of the eyelid. Unilateral autonomic symptoms are typical. Cluster headache (so called because bouts of headache cluster together for a period of time, often 4-6 weeks. The timing of attacks is often at night and in cluster lasts 15 mins to 2 hours. If the attacks are more frequent and briefer, another one of the TACs such as SUNCT (short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing) is possible. Ironically SUNCT produces the briefest headache and the longest name!

Contrasted with migraine, patients are agitated, distressed, pace around and the pain can be so severe they may scream or bang their head against the wall. Seeing a cluster headache patient during an episode as an SHO is something I will never forget. This can be helpful in distinguishing cluster from migraine. Though more commonly described in men, women do get cluster headaches. High flow oxygen can be very helpful in aborting attacks,

Hemicrania continua: a slightly odd form of primary headache which is worth knowing about as it responds so well to treatment with indomethacin (in fact response to indomethacin clinches the diagnosis). The headache is always locked to one side of the head and is continuous (hence the name!) though can wax and wane. The eye can redden or water on that side so likely it is a cousin of the TACs

if you want to know more about TACs, visit the OUCH UK website (yes really!)

Primary thunderclap headache: a true diagnosis of exclusion. It is a brave (and foolhardy) doc who diagnoses this before ruling out secondary causes. There are no clinical differences between this and a SAH and therefore tests such as imaging and an LP for xanthochromia (blood breakdown products) must be carried out and be normal first. We would often carry out other investigations which are beyond the scope of this piece, such as imaging blood vessels to see if vasospasm may have produced the pain also. There is a form of thunderclap headache which occurs with exertion and more difficult for the patient to discuss, during sexual intercourse (they may just say ‘exertion!’). However, remember that exertion can be a trigger for an SAH so this story does not exclude SAH!


  • Most headaches are primary headache disorders such as migraine
  • However, the bulk of headache work in the NHS outside of neurology outpatients is seeking after and ruling out red flags of secondary headache causes which can cause mortality and morbidity
  • Try to think about what factors worry you about a patient. Think about relevant red flags, whether they are present in this case and how you go about investigating them
  • Headache diagnosis is helpful for patients; it allows their anxiety to be managed and the right treatment to be provided. Beware the “it’s not a bleed, discharge” method. Patients come to us for answers!
  • The key in headache diagnosis is listening and looking. History is 90% and examination most of the rest!
you can learn more by listening to the headache lecture on TeesNeuro here