The term 'headache' covers any pain around the head, face or neck area.

Most headaches are not serious. But seek medical attention if:

• you have a very bad, blinding headache that appears suddenly and gets worse
• you have had a severe head injury
• you get a sudden headache when you cough, laugh, sneeze or move
• you have other symptoms like slurred speech, confusion, weakness, drowsiness, memory loss, or trouble walking
• you have a fever, stiff neck, rash, pain in the jaw when you chew, vision problems, a sore scalp or bad pain in an eye.

There are two main types of headache:

• primary - which often "just happen" and are not caused by another injury or illness
• secondary - which are caused by some underlying health condition.

Primary headaches

Primary headaches are the most common. They include tension headaches, migraine and cluster headaches.

Primary headaches can be caused by a number of things including:

• stress
• eye strain or squinting
• poor posture
• dehydration
• drinking too much alcohol or eating certain foods
• lack of sleep
• poor posture
• skipping a meal.

Sometimes there is no obvious cause.

Secondary headaches

Secondary headaches have a separate cause, such as illness. They include headaches caused by drinking too much alcohol or a head injury or concussion.

Headaches in women may be caused by hormones, and some women notice a link between headaches and their periods. Hormonal changes due to taking the Pill, menopause and pregnancy can also be triggers for headaches.

Some headaches can even occur as a side effect of medication, such as painkillers. People sometimes get headaches when they’re unwell. For example, you may get a headache when you have a cold, sinusitis, flu or an allergic reaction.

There are a lot of illnesses that can cause headaches. See your doctor if you are getting more headaches than usual, they are worse or don’t improve with over the counter medicines, or they are stopping you from working or sleeping.

Dehydration

Lack of fluids can cause dehydration and is a common cause of headaches. Fluids are needed for the body to function correctly and may be lost through:

• illness such as vomiting or diarrhoea
• vigorous exercise
• excessive sweating
• alcohol
• having large amounts of drinks containing caffeine such as coffee, tea or cola, which cause you to urinate frequently
• working in hot weather or high-temperature environments.

If you are getting a lot of headaches or concerned talk to your doctor.