Headache: Common Causes & Warning Signs You Shouldn't Ignore

Headaches are very common and most are not caused by a serious condition. They can occur because of stress, dehydration, missed meals, infections, migraine and many other factors. However, a new, sudden or unusually severe headache can sometimes require urgent medical assessment.

This guide explains common headache causes, simple measures that may help, and warning signs that should not be ignored.

What can cause a headache?

Common causes and triggers include:

• Stress or emotional tension
• Not drinking enough fluids
• Skipping meals
• Lack of sleep or changes in sleep
• Cold, flu or other infections
• Alcohol
• Eye strain or vision problems
• Poor posture or muscle tension
• Migraine
• Some medicines or frequent use of pain-relieving medicines

Headache can also occur with medical conditions that require assessment. The cause cannot always be determined from the location or intensity of pain alone.

Common types of headache

Tension-type headache

Tension-type headaches are common and may feel like pressure or tightening around the head. Stress, muscle tension and other factors can contribute.

Migraine

Migraine can cause moderate to severe headache and may be accompanied by nausea or increased sensitivity to light or sound. Some people experience visual or other neurological symptoms called an aura.

Headache associated with infection

Headache can occur during a cold, flu or other infection, particularly when fever or other symptoms are present.

Other causes

Less common but important causes include problems involving blood vessels in the brain, bleeding, infections such as meningitis, head injury and other neurological conditions. These possibilities become more important when a headache has unusual features or occurs with other warning symptoms.

What can you do for a mild headache?

If your headache is mild and similar to headaches you have experienced before, simple measures may help:

• Drink enough water.
• Eat regular meals and avoid prolonged fasting.
• Get adequate sleep and rest.
• Try to relax if stress appears to be contributing.
• Reduce prolonged screen or eye strain where possible.
• Avoid alcohol while you have a headache.

Some adults may use an appropriate over-the-counter pain reliever, such as paracetamol or ibuprofen, when it is safe for them to do so. Follow the product instructions and consider your other medicines, allergies, pregnancy status and medical conditions before taking medication.

When should you see a doctor?

Consider medical assessment if:

• Your headaches keep coming back.
• Your usual headache pattern changes.
• Your headaches are becoming more severe or frequent.
• Pain-relieving medicines no longer help as they previously did.
• A headache lasts for several days.
• Headaches repeatedly wake you from sleep.
• You develop headaches for the first time later in adulthood.
• You need pain medicines frequently to control headaches.
• You have persistent headaches together with other symptoms that concern you.

Headache warning signs: when is it an emergency?

Headache with fever and stiff neck

Headache together with fever and a stiff neck can be a sign of meningitis. Other symptoms can include vomiting, sensitivity to light and confusion. Meningitis can be serious, and someone with these symptoms should receive urgent medical assessment.

Headache and stroke warning signs

A sudden severe headache can sometimes occur with stroke. More important warning signs include sudden weakness or numbness on one side, difficulty speaking, sudden vision problems, dizziness or loss of balance.

If these symptoms occur suddenly, treat them as an emergency and seek immediate emergency medical care. Do not wait for an online consultation.

Headache after a head injury

A new or severe headache following a significant head injury requires medical assessment. Seek urgent care particularly if the headache is worsening or accompanied by vomiting, confusion, drowsiness, weakness, seizures or loss of consciousness.

What information can help a doctor evaluate a headache?

If you are seeking medical advice, it can be useful to note:

• When the headache started
• Whether it began suddenly or gradually
• Where the pain is located
• How severe the pain is
• How long each episode lasts
• How often headaches occur
• Other symptoms such as nausea, vomiting or visual changes
• Possible triggers such as missed meals, stress or lack of sleep
• What medicines you have taken and whether they helped

Frequently asked questions

Related health guides

• Fever in Adults: Causes, What to Do & When to See a Doctor
• Cold & Cough: When Do You Need Medical Advice?
• Stomach Pain: Common Causes & When to Seek Care
• View all Doctor24 Health Guides

This article is for general educational information and does not replace professional medical evaluation. Doctor24 is not an emergency service. If you have a medical emergency, seek immediate in-person emergency care.