If you’ve noticed an uptick in how often you’ve had a headache this summer, you’re not alone. Allergies, travel stress, dehydration, humidity and extreme heat can all lead to headaches.

“Although there are several types of headaches, migraine and tension headaches are the most common,” says neurologist Michelle Noel, DO. A migraine starts deep within the brain. It involves the brain stem, nerves, and blood vessels. The brain releases chemicals that inflame and irritate the nerves and blood vessels, causing pain.

Tension headaches may be triggered by tense muscles in the neck and shoulders, which may cause pain to be referred to the head and behind the eyes.

Only rarely are headaches a sign of a serious medical condition, but if you experience new or worsening headache symptoms that are not like your typical headaches, seek medical attention immediately.

What’s the difference?

Migraine headaches

A migraine causes throbbing pain felt on one or both sides of the head. This headache may also be preceded or associated with changes in sight — like seeing spots or flashes of light, known as aura — and changes in sensations or the ability to speak. You may feel nauseated or vomit. Pain may last for four to 72 hours.

Tension headaches

This type of headache is usually a dull ache or a sensation of pressure on both sides of the head. It may be associated with pain or tension in the neck and shoulders. Depression, anxiety, and stress can cause a tension headache. The pain may not have a definite beginning or end. It may come and go, or it may seem to never go away.

When to get medical help

Call your doctor for headaches that happen along with any of these symptoms:

• Sudden, severe headache that is different from your usual headache pain

• Loss of vision or blurry vision

• Recurring headaches or headaches that worsen over time

• Ongoing numbness or muscle weakness

• Pain following a head injury

• Memory loss

• Coordination loss

• High fever along with a stiff neck

Get a handle on your headaches

Some headaches can be prevented by avoiding what triggers them in the first place. To learn more about what causes your headaches, keep track of a few important details when you feel one start:

Date and time of day: Is it early morning or late at night? Bright sunlight or glare from vehicle lights can trigger pain.

Warning signs or symptoms: Did you feel nauseated or have a change in vision?

Type and intensity of pain: Is it throbbing, stabbing, or blinding? Is it constant or in waves?

Location of pain: Do you feel it behind your eyes, back of your head, or at one specific point?

What happened before: Jot down details about your environment or social interactions.