Headache

A headache is pain or discomfort in part or all of your head. It may also affect your face or upper neck. The pain can begin gradually or suddenly and may last from minutes to several days.

Headache is a symptom, not a single disease. Some headaches occur on their own, such as migraine or tension-type headache. Others are caused by an illness, injury, medicine, or another health problem.

Most headaches are not caused by a dangerous condition. However, the way a headache starts and the symptoms that come with it can sometimes signal a need for urgent care.

Headache pain may be dull, tight, throbbing, sharp, burning, or stabbing. It can affect one side, both sides, the forehead, the temples, behind an eye, or the back of the head.

Other symptoms may include:

• Sensitivity to light, sound, smells, or movement
• Nausea or vomiting
• Tight neck or shoulder muscles
• Watery eyes or a blocked or runny nose
• Vision changes, tingling, or difficulty speaking before the pain
• Trouble concentrating or carrying out normal activities

Details such as when the pain started, how quickly it developed, and whether it differs from previous headaches can help identify the cause.

Common causes include tension-type headache and migraine. Tension-type headache often causes pressure or tightness on both sides of the head. Migraine commonly causes moderate or severe pain, often with nausea or sensitivity to light and sound. It may affect one side or both sides.

Headaches can also occur with viral illnesses, poor sleep, missed meals, dehydration, stress, changes in caffeine intake, or long periods of screen use. Dental problems and jaw-joint strain can cause pain that spreads into the head.

Less common causes include cluster headache, nerve pain, medication-overuse headache, and problems involving the eyes, ears, nose, or sinuses. Medication-overuse headache can develop when medicines used for short-term relief are taken frequently. The risk depends on the medicine and how often it is used.

Urgent causes are uncommon but include bleeding around the brain, stroke, meningitis, very high pressure inside the eye, and inflammation of an artery near the temple. Carbon monoxide exposure can cause headache with dizziness, nausea, weakness, or confusion, sometimes affecting several people in the same building.

Call emergency services now if a headache:

• Becomes extremely severe within seconds or about a minute
• Comes with new weakness, numbness, facial drooping, confusion, or trouble speaking
• Occurs with fainting, a seizure, severe drowsiness, or difficulty walking
• Follows a head injury and is worsening, especially with repeated vomiting
• Comes with sudden loss of vision or a painful red eye
• May be linked to carbon monoxide exposure

If carbon monoxide is possible, move into fresh air if you can do so safely and call emergency services. Do not re-enter the building until it has been assessed.

Seek urgent same-day medical advice for a new or unusually severe headache with fever, a stiff neck, a rash, or feeling seriously unwell. Also get prompt advice if you are pregnant or recently gave birth and develop a new severe headache, particularly with vision changes or upper abdominal pain.

A new headache after age 50 needs prompt assessment if it comes with scalp tenderness, jaw pain while chewing, or vision changes. You should also seek same-day advice for a new headache if you have a weakened immune system, cancer, or take medicine that reduces blood clotting.

Book a routine appointment if headaches are becoming more frequent, changing in pattern, disturbing sleep, or affecting work, school, or daily activities. Arrange follow-up if you regularly need pain medicine or self-care is no longer helping.

A healthcare professional will ask where the pain is, how it began, how long it lasts, and what other symptoms occur. They may ask about injuries, illnesses, medicines, menstrual or pregnancy history, sleep, caffeine, and previous headaches.

The examination may include blood pressure, temperature, vision, eye movements, strength, balance, reflexes, and the neck and scalp.

Most people with a familiar headache pattern and a normal examination do not need a brain scan. Blood tests, eye tests, CT or MRI scans, or a lumbar puncture may be considered when symptoms or examination findings suggest a particular cause. A lumbar puncture tests fluid from around the brain and spinal cord.

Treatment depends on the cause and may include medicine for pain or nausea, preventive treatment for recurring headaches, or treatment of an underlying illness.

For a mild, familiar headache, it may help to:

• Drink water and eat if you have missed a meal
• Rest in a quiet, dim room
• Use a cool or warm pack
• Take breaks from screens and relax tense neck muscles
• Keep sleep, meals, and caffeine intake reasonably consistent

Over-the-counter pain medicines may help some headaches. Follow the product label, and ask a pharmacist or healthcare professional which options are suitable if you are pregnant, take other medicines, or have other health conditions.

Frequent use of short-term headache medicine can sometimes make headaches more frequent. Do not stop a prescribed medicine suddenly without advice.

Headaches caused by a minor illness, dehydration, or missed sleep often improve when the trigger resolves. Migraine, tension-type headache, and cluster headache can return, but treatment may reduce their frequency or severity.

A diary can help you record timing, symptoms, possible triggers, menstrual periods, and medicines used. Bring it to an appointment if headaches continue. Seek reassessment if the pattern changes or new symptoms appear.

Is every severe headache a migraine?

No. Migraine can be severe, but headache intensity alone does not identify the cause. How quickly the pain started and which other symptoms are present are also important.

Can dehydration cause a headache?

Yes. Headache may occur when you have not had enough fluid, especially with heat, exercise, vomiting, or diarrhea. Persistent headache may have another cause.

Does high blood pressure cause headaches?

Most headaches are not caused by routine changes in blood pressure. A headache with severely raised blood pressure and symptoms such as chest pain, breathlessness, confusion, or vision changes needs urgent assessment.

Do I need a brain scan?

Usually not. Scans are most useful when the history or examination suggests bleeding, pressure, injury, infection, or another structural problem. A clinician can assess whether imaging is appropriate.

Is a “sinus headache” always sinusitis?

No. Migraine can cause facial pressure, watery eyes, and nasal symptoms. Sinus infection is more likely when facial pain occurs with symptoms such as thick nasal discharge, reduced smell, or fever.