Many people experience headaches, which can have many causes like stress, muscle tension, sinus issues or side effects from medication. However, recurrent or severe headaches might indicate a deeper problem, and it's best to consult a doctor for an evaluation.

Intense pain on the left side of the head may have various origins including headaches, migraines, injuries, or infections. It is crucial to visit a physician to identify the root cause and get appropriate treatment.

What causes headaches on the left side?

There could be many causes for pain in the back of the head's left side, like,

1. Migraine

This is a type of headache which is observed as very common among people and is characterized by moderate to severe pain, accompanied by symptoms like nausea, vomiting, and sensitivity to light and sound commonly. They can affect one or both sides of the head, and the pain is usually described as a pulsing or throbbing sensation.

2. Tension

These are the most common headaches caused by muscle tension in the head, neck, and scalp. Stress, poor posture, or other factors are one of the major factors that lead to muscle tension.

3. Cluster

Cluster headaches are rare and are characterised by severe pain on one side of the head, usually around the eye or temple. The pain is described as burning or stabbing like a hot poker. Other symptoms can include a drooping eyelid, a red and watery eye, a runny or stuffy nose, and a swollen face on the affected side. Cluster headaches often occur in "clusters," meaning they happen several times a day for weeks or months at a time, followed by periods of remission where the headaches do not occur.

4. Sinus

Sinus headaches are not common, but they can be quite intense and might be mistaken for migraines. These are caused by inflammation of the sinuses, the air-filled spaces in the skull. They can be caused by infections, allergies, or other conditions that lead to sinus inflammation.

5. Concussion

A concussion is a form of brain injury that can result in unilateral headache pain. This occurs when the brain suffers a hit, jolt or impact from a blow to the head, which causes the brain to move or collide with the inside of the skull. 

Lifestyle factors contributing to headaches

Poor lifestyle choices could also result in pain in the back of the head's left side. Some of the lifestyle choices that could be resulting in headaches are:

1. Diet: Skipping meals or consuming specific foods and drinks can trigger migraines.
2. Sleep: Insufficient or inconsistent sleep schedule can lead to migraines and headaches.
3. Stress: High-stress levels can trigger migraines.
4. Environmental factors: Polluted air, strong odours, bright lights, flashing lights, or weather changes can all cause headaches.
5. Physical activity: Regular exercise can prevent headaches, but over-exertion can also trigger headache attacks.

This is why it is important to lead a healthy lifestyle to prevent headaches and other serious problems as well.

Health conditions

1. Infections

Severe, unilateral head pain can also be caused by rare bacterial and viral infections that affect the head. Two examples of this type of infection are meningitis and encephalitis, both of which can lead to debilitating headaches and other severe symptoms. Meningitis is an infection of the tissues that surround the brain, while encephalitis is an inflammation of the brain itself.

2. Allergies

Allergies can cause headaches on the left side of the head. This happens when certain things, such as food, drinks, or environmental factors, cause an immune response in the body that leads to inflammation of the sinuses, resulting in pain in the forehead and cheeks.

Excessive Medication Dependence

Using headache medicines excessively can also result in further headaches, including pain in the back of the head's left side. This happens when these medications are taken frequently in a week, known as medication overuse or rebound headaches. Symptoms of this type of headache include experiencing almost daily headaches that start when you wake up in the morning. 

Medications that can cause these types of headaches include aspirin, acetaminophen, ibuprofen, naproxen, aspirin and acetaminophen combined with caffeine, triptans such as sumatriptan and zolmitriptan, ergotamine derivatives such as Cafergot, and prescription pain medications such as oxycodone, tramadol, and hydrocodone.

Headaches caused by Neurological conditions

Sometimes, a persistent headache in the back left of the head can be due to neurological conditions like 

1. Occipital Neuralgia

A rare and painful headache that mainly affects one side of the head and is caused by pressure on the nerves, resulting in sharp, throbbing pain in the neck, behind the ears, or back of the head.

2. Giant Cell Arteritis

An inflammation of the temporal artery on the side of the forehead can also lead to left-sided headaches. It can be serious, as it can disrupt blood flow and cause other symptoms such as jaw pain, loss of vision, fever, and fatigue. 

3. Trigeminal Neuralgia

A chronic pain condition caused by damage to the trigeminal nerve, which can result from compression of blood vessels, multiple sclerosis, stroke or head trauma among other conditions. The pain associated with trigeminal neuralgia can range from sudden and stabbing to a more consistent aching and burning.

When is it necessary to consult a doctor?

It's important to remember that while most headaches do not require medical attention, in some cases the pain may be caused by a more serious underlying condition. It's crucial to seek emergency medical help if you have a loss of consciousness or rapid onset of severe headaches.

It's also important to contact your healthcare provider if you have:

1. Fever
2. Stiff neck
3. Memory problems
4. Confusion
5. Coordination issues
6. Vision problems
7. Pain in one eye
8. Difficulty swallowing or chewing besides a headache.

Frequently Asked Questions

Should we worry about pain on the left side of the head?

Usually, headaches are normal and fade away after a while with or without medications. But if you are experiencing any severe pain accompanied by symptoms such as nausea, vomiting, or sensitivity to light or sound then it’s always a good idea to consult a doctor.

Is left-side head pain life-threatening?

Headaches on the left side are mostly caused due to migraines, tension, stress, etc., and are usually not life-threatening. But if the headaches are severe, it is important to consult a doctor.

What are the symptoms of left-side head pain?

Headache on the left side may include symptoms like nausea, vomiting, or sensitivity to light or sound. Other symptoms like fever, stiffness in the neck, confusion, slurred speech, coordination problems, vertigo, vision problems, or difficulty swallowing or chewing are also observed.