What are the causes of headache on the left side?

Left-sided headaches usually resolve with a simple pain reliever, massage, or some relaxation. In any case, if it occurs frequently or is too intense, it is important to see a doctor.

Last update: 21 January, 2022

Left-sided headache is a common condition that, by itself, should not be a cause for concern. The location gives some clues about the origin of the problem.

As in other areas, the headache on the left side can come on slowly or suddenly. Sometimes it is sharp and other times it is stabbing or throbbing. It stays in a specific area or radiates to nearby areas, such as the neck and eyes.

If it is accompanied by other symptoms, such as vomiting, fever or mental confusion, it is likely to be associated with a health difficulty that requires immediate attention.

The most common causes of headache on the left side

There are many factors that can cause a left-sided headache.. They range from an inappropriate lifestyle to a brain tumor. Most of the time they obey a simple origin that can be corrected.


Improper lifestyle is the main cause of left-sided headache. It has to do with the consumption of food or substances and with unhealthy habits.

Factors such as the following fall into this category:

  • Skipping meals: the brain needs the glucose it takes in from food to function properly. If food is not eaten for longer than is convenient, pain can be one of its effects.
  • Stress: stress causes muscles to tense. Likewise, it causes biochemical changes that put the brain on alert. Both of these factors contribute to headaches.
  • Poor sleep: not sleeping enough hours or not getting restful sleep are two common causes of left-sided headache.
  • Some foods: Certain products, especially those that contain preservatives, can give you a headache. Processed meats, aged cheese, red wine and nuts are part of those meals.
  • Alcohol consumption: Many alcoholic beverages contain ethanol, and this substance causes blood vessels to dilate. The result is the headache.
  • Compression: helmets or very tight hats, as well as hairstyles that pull the scalp can also cause headaches.
Red wine brings together a series of substances that are capable of causing headaches when consumed in excess.


There are some medications that can cause the so-called rebound effect. This is that excessive consumption gives rise to the symptom to be eliminated. If this happens, the pain almost always occurs after waking up, in the first hours of the day.

Some of the drugs that can cause rebound headache on the left side are the following:

  • Ibuprofen.
  • Aspirin.
  • Paracetamol.
  • Naproxen.

infection or allergy

Colds and flus often cause sinus passages to become blocked. and it is possible that this triggers a headache. Other more serious infections, such as encephalitis and meningitis, also cause the pain, but it is very intense and accompanied by other important symptoms, such as seizures, fever, and stiff neck.

Allergies also cause sinus congestion. This causes pressure on the cheeks and behind the forehead. On many occasions they lead to a headache on the left side.

neurological problems

Headache on the left side can be a consequence of neurological problems. From that perspective, the main origins are the following:

  • Temporal arteritis: also known as giant cell arteritis. It is the inflammation of the blood vessels on both sides of the head.
  • Occipital neuralgia: Irritation of the nerves in the upper neck and base of the skull can cause a headache on the left side and in the back. This is severe, intense and stabbing.
  • Trigeminal Neuralgia: the pain is felt in the face, but can also spread to the head.

More serious causes

Headache on the left side can have a more serious origin, such as the following:

  • High blood pressure: Usually high blood pressure causes no symptoms, but some people do have a headache.
  • Concussion: It is a traumatic brain injury as a result of a blow.
  • Glaucoma: This is an eye pathology that usually causes a severe headache, as well as eye pain and blurred vision.
  • stroke: It occurs from a hemorrhage inside the brain or from a clot that blocks blood flow in that area. One of the common symptoms is a fairly severe headache that comes on suddenly.
  • Brain tumor: it does not always cause specific signs, but it could be expressed with sudden and intense headache.

When to see a doctor

Most of the time, the headache on the left side can be treated at home with a common pain reliever. However, as we have pointed out, it should not be underestimated.

You should consult a doctor if the pain has the following characteristics:

  • Too much intensity: It prevents you from getting out of bed or performing daily activities.
  • Waking up at night: leads to a person not resting.
  • Gets worse over time: It may be a sign of something more serious.
  • A previous blow to the head: this situation should be reported yes or yes.

On the other hand, it is also necessary to see a doctor when this type of pain is accompanied by symptoms such as the following:

  • Neck stiffness.
  • Vision loss or double vision.
  • Weakness or numbness.
  • Confusion.
  • Speech or movement problems.
  • loss of consciousness
Strokes require immediate attention. When the headache is accompanied by neurological signs, it is necessary to consult.

How to relieve left-sided headache?

At first, what is indicated to relieve the headache on the left side is to take a bath of lukewarm water, breathe and try to relax. A nap as well as eating something light can also help. Likewise, listening to soft music and taking an over-the-counter pain reliever are good measures.

Another option is to put a warm or cold compress on the left side of the head. Inhaling the aroma of lavender oil is something that often helps to dissipate the discomfort.

The headache on the left side, in principle, should not cause alarm. The most common is that it is the effect of stress or inappropriate habits.

In case it is very intense or frequent, it is important to discuss it with the doctor. Also when accompanied by other symptoms.

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