Differential Diagnosis for Low Blood Pressure
Single Most Likely Diagnosis
- Hypovolemia: This is the most common cause of low blood pressure, resulting from decreased blood volume due to dehydration, bleeding, or other fluid losses. It is often seen in patients with severe diarrhea, vomiting, or bleeding.
Other Likely Diagnoses
- Medication side effects: Certain medications, such as diuretics, beta blockers, and ACE inhibitors, can cause low blood pressure as a side effect.
- Deconditioning: Prolonged bed rest or immobility can lead to orthostatic hypotension due to decreased muscle tone and venous return.
- Autonomic dysfunction: Conditions such as diabetes, Parkinson's disease, or multiple system atrophy can affect the autonomic nervous system, leading to orthostatic hypotension.
- Cardiac causes: Heart failure, cardiomyopathy, or valvular heart disease can reduce cardiac output, resulting in low blood pressure.
Do Not Miss Diagnoses
- Septic shock: A life-threatening condition caused by severe infection, leading to vasodilation and decreased blood pressure.
- Adrenal insufficiency: A rare but potentially fatal condition caused by inadequate production of adrenal hormones, leading to hypotension and shock.
- Pulmonary embolism: A blockage of the pulmonary arteries, which can cause sudden and severe hypotension.
- Cardiac tamponade: Fluid accumulation in the pericardial sac, which can compress the heart and reduce cardiac output, leading to hypotension.
Rare Diagnoses
- Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic hypotension due to excessive catecholamine release.
- Addison's disease: A rare condition caused by primary adrenal insufficiency, leading to hypotension and electrolyte imbalances.
- Myxedema coma: A rare but life-threatening condition caused by severe hypothyroidism, leading to hypotension and altered mental status.
- Anaphylaxis: A severe allergic reaction that can cause vasodilation and hypotension, often accompanied by other symptoms such as hives and respiratory distress.