Differential Diagnosis for Left Side Headache
- Single most likely diagnosis
- Migraine: This is a common cause of unilateral headaches that can be severe and debilitating. The fact that it's not improving with analgesics could suggest a migraine, especially if the patient experiences other migraine symptoms like nausea, vomiting, or sensitivity to light and sound.
- Other Likely diagnoses
- Tension headache: Although typically bilateral, tension headaches can occasionally present unilaterally and may not respond immediately to over-the-counter analgesics.
- Cluster headache: Known for severe, unilateral pain, often around the eye, cluster headaches can occur on one side of the head and may not respond well to conventional analgesics.
- Sinusitis: If the headache is accompanied by facial pain, nasal congestion, or fever, sinusitis could be a likely cause, especially if the pain is localized to the left side of the face.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Subarachnoid hemorrhage: A sudden, severe headache (often described as "the worst headache of my life") could indicate a subarachnoid hemorrhage, which is a medical emergency.
- Temporal arteritis: This condition, which typically affects older adults, can cause unilateral headaches and is a medical emergency due to the risk of vision loss if not promptly treated.
- Brain tumor: Although rare, a brain tumor could cause localized headaches, especially if it's pressing on nerves or causing increased intracranial pressure.
- Rare diagnoses
- Occipital neuralgia: Involves the nerves that run from the base of the skull to the scalp and can cause severe, stabbing pain on one side of the head.
- Hemicrania continua: A rare form of headache disorder characterized by continuous, unilateral pain.
- Trigeminal neuralgia: While typically involving the face, in rare cases, it can cause headache-like pain on one side of the head due to the involvement of the trigeminal nerve.