Imagem ilustrativa número 1

Left-sided headache: 6 causes (and what to do)


Left-sided headache is usually caused by blows and minor injuries to the head, ear inflammation or migraine, and may appear with other symptoms such as local swelling, nausea or fever.

Although it is not always worrying, if the headache appears together with symptoms such as weakness in some part of the body, loss of vision or a seizure, it may indicate more serious problems such as brain tumors or serious blows. In these cases, imaging tests, such as computed tomography or magnetic resonance imaging, may be indicated.

In the case of a headache on the left side that occurs frequently, it is important to consult a general practitioner for an evaluation, because the precise identification of the cause is important so that the most appropriate treatment can be initiated.

What could be a headache on the left side

To find out what may be causing your headache, please answer the following questions:

This tool should only be used to help identify the possible cause of the headache. Therefore, it should not replace a consultation with a doctor, who is the professional responsible for confirming the diagnosis and recommending the most appropriate treatment.

Main causes

The main causes of left-sided headache include:

1. Wounds and blows

Left-sided headache can be caused by injuries and light blows to that side of the head. In these cases, there are generally no symptoms other than pain and small swelling at the site, which disappear within a few days.

What to do: This type of headache tends to improve within a few days. However, if the pain is more intense or persists for more than a week, it is recommended to consult a general practitioner, who may recommend the use of painkillers such as paracetamol or dipyrone.

Furthermore, if symptoms such as vomiting, seizures or loss of consciousness occur immediately after the blow, it is important to seek an emergency room for a more detailed evaluation, as they may indicate a more serious injury.

2. Migraine

Migraines can also cause a headache on the left side, which is usually throbbing and accompanied by symptoms such as nausea, vomiting, intolerance to noise or light.

Generally, migraine pain tends to worsen with physical exertion, such as walking or climbing stairs, and other symptoms such as blurred vision or seeing lights may occur before or during the headache. Learn how to identify the main symptoms of migraine.

What to do: If you suspect a migraine, it is important to consult a general practitioner or neurologist for an assessment and start appropriate treatment, which may involve medications, such as painkillers and anticonvulsants, and changes in habits such as getting enough sleep, avoiding food and exercise. physical exercises regularly. See more details on migraine treatment options.

3. Acute otitis media

Acute otitis media is an ear infection that can cause a headache on the left side if the ear is affected on that side. Other symptoms that may arise with a headache are fever and/or discharge coming from the ear. Understand better what acute otitis media is, its causes and symptoms.

What to do: It is recommended to consult a general practitioner, pediatrician, in the case of children, or an otolaryngologist in case of suspected acute otitis media, because treatment generally involves the use of medications such as antibiotics, analgesics and antipyretics.

4. Dental infections

When dental infections, such as those caused by cavities, occur in teeth on the left side, they can cause pain on that side, usually close to the affected teeth.

In this case, the pain may worsen when touching the tooth, when drinking hot or cold drinks or even be continuous. In addition, other symptoms such as swollen gums or bleeding easily may occur, and, in more serious cases, even fever. Find out what cavities are and how to confirm the diagnosis.

What to do: If you suspect a tooth infection, it is important to consult a general practitioner or dentist for an assessment and start appropriate treatment, which may involve tooth extraction or the use of antibiotics depending on the severity of the infection.

5. Arteries temporal

Temporal arteritis is an inflammation of the vessels, which, when it affects arteries on the left side of the head, can cause symptoms such as headache on the left side, transient loss of vision and difficulty chewing.

Furthermore, the pain tends to worsen with touch, making tasks such as combing hair difficult and causing the person to avoid sleeping on the affected side, and other symptoms, such as fever and malaise, also occur.

What to do: If temporal arteritis is suspected, it is important to consult a rheumatologist, because, when the diagnosis is confirmed, appropriate treatment can improve the headache and prevent the disease from worsening, and may involve medications such as oral corticosteroids. Understand how temporal arteritis is diagnosed and treated.

6. Tumors

Although they are rare, brain tumors can also cause pain on the left side of the head in some cases, however, other symptoms such as seizures, weakness in parts of the body, nausea, vomiting and episodes of transient vision loss usually also occur.

Furthermore, the pain tends to be worse in the morning, when lying down, coughing or making intense efforts, such as when carrying weights. Learn about other symptoms of brain tumors.

What to do: When a brain tumor is suspected, it is recommended to consult a general practitioner or neurologist for imaging tests such as computed tomography or magnetic resonance imaging. If the diagnosis is confirmed, the headache tends to improve with treatment of the tumor, which may involve measures such as surgery and chemotherapy. See the main treatment options for brain tumors.

When to go to the doctor

It is important to see a doctor if:

  • Frequent headache, if there is no history of headache;
  • Weakness in part of the body;
  • Convulsive crisis;
  • Fainting;
  • Loss of vision, even if temporary;
  • Double vision;
  • History of cancer;
  • Headache that worsens over time;
  • Headache worsens when lying down or coughing;
  • Waking up at night due to headache.

In these cases, imaging tests such as magnetic resonance imaging or computed tomography may be indicated to rule out serious causes of headache, such as brain tumors, and allow the start of the most appropriate treatment.