Differential Diagnosis for Headache with Hypotension and Tachycardia
- Single Most Likely Diagnosis + Dehydration: This is a common cause of headache, hypotension, and tachycardia, especially in individuals who have not consumed enough fluids or have experienced excessive fluid loss due to vomiting, diarrhea, or excessive sweating.
- Other Likely Diagnoses + Viral or bacterial meningitis: Although less common, these infections can cause headache, fever, and alterations in blood pressure and heart rate. The presence of neck stiffness, fever, and altered mental status would increase the likelihood of this diagnosis. + Subarachnoid hemorrhage: A severe headache (often described as "the worst headache of my life") accompanied by hypotension and tachycardia could be indicative of a subarachnoid hemorrhage, especially if there are signs of increased intracranial pressure or focal neurological deficits. + Adrenal insufficiency (Addisonian crisis): This condition can cause hypotension, tachycardia, and headache due to the lack of cortisol and aldosterone production. Other symptoms might include abdominal pain, nausea, and changes in skin pigmentation.
- Do Not Miss Diagnoses + Intracranial hemorrhage or stroke: These are medical emergencies that require immediate attention. Symptoms can include sudden onset headache, alterations in consciousness, focal neurological deficits, and changes in blood pressure and heart rate. + Septic shock: Although hypotension is a hallmark, tachycardia can also be present. The combination of headache with these symptoms in the context of a suspected infection (fever, chills, etc.) should prompt consideration of septic shock. + Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic hypertension, tachycardia, and headaches. However, in some cases, especially during a crisis, hypotension can occur.
- Rare Diagnoses + Pituitary apoplexy: A condition where there is sudden hemorrhage or infarction of the pituitary gland, leading to acute headache, visual disturbances, and alterations in consciousness. Hypotension and tachycardia can occur due to the acute loss of pituitary function. + Carotid dissection: Although more commonly associated with neck pain and neurological deficits, carotid dissection can cause headache and alterations in blood pressure and heart rate due to the disruption of the carotid artery wall. + Malignant hypertension: Severe, uncontrolled high blood pressure can lead to headache, but in rare cases, it might also cause hypotension due to end-organ damage or as part of a hypertensive emergency with fluctuating blood pressures.