When someone describes pain as “left side of my brain hurt,” they are typically referring to discomfort localized to the left side of their head. The brain itself lacks pain receptors; sensations originate from surrounding tissues like blood vessels, nerves, muscles, and the scalp. This article explores common reasons for left-sided head pain and outlines when medical attention may be necessary.
Common Primary Headaches
Primary headaches are the main condition, not a symptom of another illness. Several common types frequently cause pain on one side of the head, including the left.
Migraine headaches often cause moderate to severe throbbing pain, frequently affecting one side of the head. They are commonly accompanied by sensitivity to light, sound, and smells, along with nausea or vomiting. Migraine attacks can last from 4 to 72 hours and may worsen with physical activity.
Tension-type headaches, while often diffuse, can also present unilaterally. They are typically described as a dull, non-throbbing pain or a feeling of pressure, similar to a band around the head. These headaches are generally less severe than migraines.
Cluster headaches are characterized by severe, sharp, burning, or piercing pain, almost always on one side of the head, often around the eye or temple. These intensely painful attacks can last from 15 minutes to 3 hours, occurring in cycles over weeks or months. Associated symptoms on the affected side may include a red and watery eye, drooping eyelid, stuffy or runny nose, and facial sweating.
Other Pain Sources
Left-sided head pain can also arise from conditions secondary to other issues in the head or neck, rather than being a primary headache disorder. These conditions often involve referred pain, where discomfort is felt in a different location from its source.
Sinusitis, an inflammation of the sinus cavities, can cause referred pain to the forehead or behind the eye, potentially on one side. This pain can feel like pressure and may be accompanied by nasal congestion.
Temporomandibular joint (TMJ) dysfunction, affecting the jaw joint, can lead to referred pain in the temple, ear, or side of the head. Jaw joint problems can strain surrounding muscles and nerves, causing radiating discomfort. Toothaches or dental infections, such as decay or abscesses, can also refer pain to the head due to shared nerve connections, particularly involving the trigeminal nerve.
Nerve pain conditions like trigeminal neuralgia involve irritation or damage to specific nerves. Trigeminal neuralgia causes sudden, intense, electric shock-like pain, typically on one side of the face, affecting areas like the jaw, cheek, or forehead. Occipital neuralgia, involving nerves at the back of the head, can cause sharp or aching pain that radiates to the side of the head or behind the eye. Eye strain from prolonged visual tasks can also manifest as pain around or behind the eye, which may be perceived as left-sided head pain.
When to Seek Medical Care
While most headaches are not indicative of serious conditions, certain symptoms warrant immediate medical evaluation. These “red flag” symptoms indicate a potential underlying issue.
Seek immediate medical care if you experience a sudden, severe headache described as the “worst headache of your life,” often called a thunderclap headache. This type of headache can reach maximum intensity within 60 seconds.
Medical attention is also necessary if a headache is accompanied by other concerning symptoms, including:
- Fever
- A stiff neck
- A rash
- Confusion
- Seizures
- Double vision
- Weakness
- Numbness
- Difficulty speaking
A headache following a head injury, especially if it worsens, should also be evaluated promptly. New or worsening headaches in individuals over 50, or a significant change in the pattern or severity of existing headaches, also warrant medical consultation.
How Doctors Diagnose Head Pain
Diagnosing head pain involves a comprehensive approach, starting with a detailed discussion of symptoms and a physical examination. Healthcare providers gather information about the pain’s characteristics, frequency, duration, and triggers. They also review your medical history and conduct a neurological examination to check mental status, motor strength, vision, and reflexes, looking for signs of an underlying condition.
If a primary headache disorder like migraine or tension-type headache is suspected and the neurological exam is normal, further diagnostic testing may not be immediately necessary. However, if red flags are present or a secondary cause is suspected, imaging studies may be ordered.
Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scans of the brain can help rule out serious underlying conditions such as tumors, infections, or bleeding. MRI is often preferred as it provides more detailed images and does not use radiation. Other tests, such as blood tests or a lumbar puncture, may be considered if an infection or other systemic issues are suspected.