Headache can be caused by poor posture, stress or anxiety, vision problems, bruxism (teeth grinding), and hormonal changes during menstruation or pregnancy.

In some cases, headaches may be a sign of other health problems, such as migraine, sinusitis, dehydration, or meningitis, and may be accompanied by other symptoms like nausea, vomiting, or fever.

A headache will usually improve with rest and hydration, however it is important to consult a doctor if your headache is getting worse or lasting longer than 2 days, or if you are experiencing other symptoms in addition to headache.

woman looking down with fingertips on her temples

What might be causing my headache?

Answer the following questions to find out what might be causing your headache:

This is only a tool to help identify possible causes of headache, and should not be used in place of a doctor's visit. Your doctor should be the one to confirm a diagnosis and recommend the most appropriate treatment.

Main causes

The most common causes of a headache are:

1. Poor posture

Pain in the head and neck is usually a sign of spinal problems caused by poor posture throughout the day and is not considered to be serious.

What to do: a headache related to poor posture should be managed with rest and by applying a warm compress to the neck until the pain improves.

It is important to contact your doctor right away if the pain lasts for more than 1 day or is accompanied by other symptoms. A workup will need to be done to determine the cause of the pain and arrange for appropriate treatment.

2. Bruxism

Bruxism, or teeth grinding, involves excessive grinding of the teeth or clenching of the jaw. It may occur during the day or night, and the person is often unaware that they are doing it. Bruxism results in mechanical stress on the teeth and causes tension in the muscles responsible for chewing. This can lead to symptoms like waking up in the morning with a headache or jaw pain.

What to do: it is important to see your dentist regularly and to make an appointment if you notice any symptoms of bruxism. This is so a diagnosis can be confirmed and treatment initiated. Treatment for bruxism often involves the use of a night guard while you sleep.

3. Vision problems

A headache accompanied by eye pain is usually a sign of vision problems, such as myopia (nearsightedness) or hypermetropia (farsightedness).

What to do: make sure to consult an ophthalmologist (eye doctor) if you are experiencing headaches associated with eye pain. Wearing glasses or contacts to correct your vision may help solve the problem.

4. PMS

Premenstrual syndrome (PMS) occurs during the 1 to 2 weeks leading up to your period and may include symptoms like headache, migraine, abdominal bloating, and breast tenderness.

PMS can occur due to normal changes in the levels of estrogen and progesterone during the menstrual cycle, which can also affect levels of serotonin in the brain, a hormone related to mood control and a sense of well being.

What to do: treating a headache caused by PMS may involve rest, drinking lots of water, and eating foods high in tryptophan, like bananas or avocados, for example.

Talk to your gynecologist or primary care provider if you are experiencing symptoms of PMS, especially if they are frequent or severe. A doctor may prescribe medications like analgesics or triptans to help treat the symptoms.

5. Pregnancy

Headaches are common during the first trimester of pregnancy due to hormonal changes, and may also be caused by fatigue, stress, dehydration, or low blood sugar (hypoglycemia).

However, a headache in the second half of pregnancy can be a sign of preeclampsia, especially if it is accompanied by other symptoms like abdominal pain, nausea, or vision changes.

What to do: a headache during pregnancy can be managed through rest, increasing fluids, and eating small meals every few hours. You can also try massaging your head to help relieve the pain.

It is important to contact your OBGYN or midwife if you are experiencing headaches in pregnancy. A workup may need to be done to rule out mores serious conditions like preeclampsia, a potentially life-threatening complication of pregnancy that requires immediate treatment.

Seek emergency medical attention for any signs or symptoms of preeclampsia or high blood pressure.

6. Dehydration

Dehydration can lead to severe headaches and may be caused by insufficient fluid intake, hot temperatures, or diarrhea.

Besides headache, other symptoms of dehydration include dizziness, excessive thirst, dry mouth, and fatigue.

What to do: wear light, breathable clothing to help reduce sweating and alleviate discomfort caused by excessive heat. Stay hydrated by drinking at least eight to ten 8 oz glasses of water a day. Severe cases of dehydration may require admission to the hospital for treatment with IV fluids and other medications.

7. Migraine

Migraines can cause constant head pain that is often throbbing or pulsating in nature and may last for days. Migraines are usually difficult to treat with over the counter pain medicine and may be accompanied by other symptoms like nausea, vomiting, and sensitivity to light and sound.

Read more about migraine symptoms and how they can present.

What to do: recommendations include lying down in a dark room and taking medications like analgesics or triptans, as prescribed by a neurologist or primary care provider. It is also important to identify any triggers that may help prevent migraine attacks and guide treatment.

It is important to consult your neurologist or primary care provider for pain that is severe or lasting more than a week. A further workup may be needed to identify the cause and arrange for adequate treatment.

8. Sinusitis

Headaches are a common symptom of sinusitis and the flu. A sinus headache may feel like pressure behind the forehead, eyes, and cheeks, and is caused by inflammation of the nasal sinuses in those regions.

What to do: salt water nasal spray can be used to help relieve a sinus headache, as well as nebulizer treatments and other medications prescribed by your doctor for treatment of a sinus infection. Reducing inflammation will help relieve the pain.

9. Meningitis

Meningitis is inflammation of the membranes that cover the brain and is often caused by infection with viruses, bacteria, fungi, or parasites. A bad headache is one of the most common symptoms of meningitis.

In addition to headache, other symptoms of meningitis may include a sudden, high fever; difficulty moving your neck and touching your chin to your chest; and seizures.

What to do: meningitis is considered a medical emergency and requires admission to the hospital for treatment with antibiotics, antivirals, antiparasitics, or antifungals, depending on the cause of the infection. Read more about sinusitis treatment, which may involve the use of medications and home remedies.

10. Stress and anxiety

Excessive stress or anxiety can cause tension in the muscles of the head, shoulders, neck, and back, resulting in muscle spasms and tension headaches. A tension headache usually starts with pain at the front of the head and behind the eyes that spreads to the rest of the head and down the neck.

This type of headache usually happens at the end of the day or following very stressful events.

What to do: techniques to reduce stress and alleviate anxiety are the most effective ways of preventing this type of muscle pain. It is also important to maintain a healthy diet, regular exercise, good time management, and adequate rest.

Other ways to help manage stress and anxiety include massage and talk therapy. Anxiety may also need to be treated with medications, which are usually prescribed by a psychiatrist.

11. COVID-19

Headache is a symptom of COVID-19, which usually involves other symptoms such as generalized muscle pain (body aches), sore throat, fever, persistent dry cough, and excessive fatigue.

Read more about COVID symptoms and complete our online symptom checker if you suspect you may have COVID-19.

What to do: follow recommendations from your doctor or primary care provider about what medications to take to help with your symptoms. These may include analgesics and antipyretics.

It is important to isolate at home if you are diagnosed with COVID-19 to avoid spreading the infection to others.

When to see a doctor

It is important to see a doctor for a headache caused by trauma such as an accident or blow to the head. You should also see a doctor for a worsening headache or a headache lasting longer than 2 days.

Seek emergency medical attention if you are experiencing a headache and any of the following symptoms:

Fever above 100.4ºF (38ºC);
Neck pain or difficulty touching your chin to your chest;
Vomiting;
Dizziness;
Difficulty seeing or walking;
Seizures.

Further workup involving exams like a computed tomography (CT) scan or magnetic resonance imaging (MRI) may be needed to help diagnose the problem and guide treatment.

Why Do I Have A Headache? (Online Quiz & 11 Causes)