Primary cough headache: causes, tests and treatment

A primary headache is one that is not caused by another disease. Primary cough headache is a rare example with a very specific trigger. OUCH(UK) defines it as a headache with sudden onset that lasts from one second to 30 minutes and is brought on by, and occurs with, coughing, straining or a Valsalva manoeuvre, which means forcible breathing out against a closed airway.

Doctors split cough-triggered headaches into two groups. Primary ones have no identifiable structural cause. Secondary ones are set off by a separate problem, and NICE Clinical Knowledge Summaries list posture and Valsalva manoeuvres among the triggers to ask about when assessing any headache. The difference is vital, because the primary form is usually harmless while the secondary form needs investigation.

OUCH(UK) describes the pain as moderate to severe and sharp, stabbing, splitting or even explosive. It begins immediately or within seconds of the trigger. It can occur on both sides of the head, and most people also have a continuous dull headache between attacks.

The disorder is described as episodic, lasting between two months and two years. In other words, the attacks tend to come in a long phase and then go away. Because the pain is short-lived, treating each single attack as it happens is not generally considered, which is why prevention matters more than painkillers taken afterwards.

• Pain starts at once or within seconds of coughing or straining.

• It lasts from about a second to half an hour.

• It may be felt on both sides of the head.

• A dull background headache may linger between attacks.

• Sustained exercise does not trigger it, according to OUCH(UK).

The list of triggers is wider than the name suggests. OUCH(UK) includes coughing, sneezing, nose blowing, laughing, crying, singing, lifting a heavy object, straining on the toilet and stooping. Anything that briefly raises pressure inside the chest and abdomen can act as the spark.

Writing down when attacks happen can help your doctor. NICE Clinical Knowledge Summaries suggest a headache diary kept for at least 8 weeks when the primary diagnosis is uncertain but a secondary cause has been excluded. The NHS also suggests a diary to work out triggers. Note the date, the trigger, how long each attack lasted and anything that came with it.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 if you or a child has a headache triggered or made worse by coughing, sneezing, bending down or exercising. NHS inform says to seek advice urgently if a headache is triggered suddenly by coughing, laughing, sneezing, changing posture or physical effort. This is advice for a new headache with this pattern, not a sign that something serious has been found.

The reason is that the same pattern can appear with brain tumours and with disorders of the back part and base of the brain. OUCH(UK) says an MRI scan is therefore often recommended. Other symptoms raise the level of concern, so treat the situation as urgent if any of the following appear alongside a headache.

• Call 999 or go to A&E, the NHS says, if a headache comes with a seizure, numbness or weakness in the body or face, or sudden and extremely painful onset.

• The same applies to a headache after a head injury within the last 3 months, or with difficulty speaking, balancing, walking or remembering.

• Drowsiness, confusion, loss of vision, a rash that does not fade under a glass, or a very high temperature with a stiff neck also need emergency care.

• Ask for an urgent GP appointment or call NHS 111 for a headache with vision or eye problems, or with vomiting.

A GP or neurologist asks about onset, duration, pattern and triggers. NICE Clinical Knowledge Summaries say assessment should look for red flags and include examination of vital signs, neck and face and a neurological examination, including a look at the back of the eye.

The CKS summary also says that investigations are generally not needed to diagnose a primary headache. Cough headache is the exception to a relaxed approach, because of the pattern described above. A specialist may therefore arrange an MRI of the brain to look for structural causes, and a normal scan in a person with a typical story supports the primary diagnosis.

OUCH(UK) says acute treatment of individual attacks is generally not considered because they are so short and the triggers so varied. Instead, the preventive medicine is the focus. It states that primary cough headache responds almost absolutely to indomethacin, an anti-inflammatory drug available on prescription.

Indomethacin can upset the stomach and is not suitable for everyone, so it should only be started and adjusted under medical guidance. A prescriber will weigh up existing conditions, other medicines and the person's age. Simple measures such as treating a persistent cough, avoiding constipation and straining and being careful with heavy lifting may reduce how often attacks are provoked, although these are practical suggestions rather than advice from the sources read.

Because it is episodic, most people can expect the phase to end. OUCH(UK) puts the usual duration at two months to two years. People often worry that headaches this sudden must mean a serious illness. When the scan is clear and the pattern is typical, the reassurance is real, although any change in pattern deserves a fresh review.

Cough headache should be kept distinct from other headache types. NICE Clinical Knowledge Summaries describe migraine, tension-type headache and trigeminal autonomic headaches such as cluster headache as separate primary headaches, and each has its own treatment. Related patterns, such as headaches linked to exercise or sudden thunderclap headaches, are covered on their own pages.

Start with a GP or NHS 111 if the headache is new. The GP can examine you and refer you to a neurologist if imaging or specialist advice is needed. Some people choose a private neurology appointment or MRI to speed this up, and the same rules apply: a headache with red flags goes to urgent or emergency care rather than a routine booking.

Whichever route you choose, bring your headache diary, a list of medicines, and a description of every trigger. If a medicine such as indomethacin is prescribed, ask how long to continue and what side effects to watch for.