Most headaches occur because something is wrong with the nerves, blood vessels and/or muscles in your head and neck. When the muscles or blood vessels (or both) undergo stress, irritation or change, the surrounding nerves may be activated, sending pain signals to the brain, which then sets off a headache. Keeping a diary is very helpful in identifying the potential factors that may be causing your headache.

Headaches can be triggered by the following:

1. Illness: An infection, cold or fever can bring on a sudden headache

2. Head trauma or stroke

3. Genetics: Headaches may run in the family

4. Environmental factors such as: the weather, noise, strong odours, strong lighting and cigarette smoke

5. Emotional or physical stress in tension headaches

6. Certain foods and drinks: e​xamples include caffeine, alcohol, MSG, nitrites, aspartame and chocolate

According to the Department of N​eurology, National Neuroscience Institute (NNI), a member of the SingHealth​ group, it is important to exclude sinister causes of headache, including brain tumours, brain infection or vascular malformations, when headaches are persistent, or have a different character from previous headaches. 

If sinister causes are excluded, persistent headaches are often related to poor lifestyle. Measures to reduce stress, having physical exercise and establishing a regular sleep cycle are often helpful in such cases.

Headache can be broadly divided into two groups: primary and secondary.

Migraines, cluster headaches and tension-type headaches are primary headaches, while secondary headaches are due to an underlying problem in the head or neck, including bleeding in the brain, infections, tumour, or meningitis and encephalitis.

It is important for your doctor to determine the type of headache you have, so that he/she will be able to decide on the most suitable treatment. Treating a secondary headache involves resolving the root of the pain, while a primary headache will be treated differently.

Ref: U11

Check out other articles on headaches:

Headaches: Types and Common Causes

Primary Headaches: The Most Common Headache

How to Prevent Headaches Naturally

Headache vs Migraine: How to Tell the Difference