What Causes Mood Swings? Common & Serious Causes Explained
Mood swings can be caused by Cushing's Syndrome, Testosterone Deficiency (Low T), Bipolar Disorder and other conditions. Learn which causes are serious, which are benign, and when to seek urgent medical evaluation.
Updated March 27, 2026
Mood swings has multiple causes, ranging from benign to serious. The most common include Cushing's Syndrome, Testosterone Deficiency (Low T), Bipolar Disorder. Cushing's syndrome results from prolonged exposure to high cortisol levels, causing central obesity, moon face, buffalo hump, skin thinning, and hypertension. The most common cause is exogenous corticosteroid use; endogenous causes include pituitary or adrenal tumors.
Clinical Context
The causes of mood swings range from benign to serious. Identifying the underlying cause requires clinical evaluation. Common causes include Cushing's Syndrome, Testosterone Deficiency (Low T), Bipolar Disorder, Borderline Personality Disorder (BPD), and others.
Clinical Pathway
Mood swings — Symptom HubSymptomCushing's Syndrome — Full Condition GuidePrimary CauseCushing's Syndrome — Differential DiagnosisDifferentialCushing's Syndrome vs. Metabolic Syndrome — Comparisonvs.Testosterone Deficiency (Low T) — Full Condition GuideCauseBipolar Disorder — Full Condition GuideCauseBorderline Personality Disorder (BPD) — Full Condition GuideCauseFrequently Asked Questions
Why do I have mood swings? common & serious causes explained?+
Mood swings has multiple causes, ranging from benign to serious. The most common include Cushing's Syndrome, Testosterone Deficiency (Low T), Bipolar Disorder. Cushing's syndrome results from prolonged exposure to high cortisol levels, causing central obesity, moon face, buffalo hump, skin thinning, and hypertension. The most common cause is exogenous corticosteroid use; endogenous causes include pituitary or adrenal tumors.
What is the most common cause of mood swings?+
Common causes include Cushing's Syndrome, Testosterone Deficiency (Low T), Bipolar Disorder. The most likely cause depends on age, associated symptoms, and medical history.
When is mood swings dangerous?+
Seek medical attention if mood swings is persistent, worsening, sudden in onset, or accompanied by other concerning symptoms.
Can mood swings be caused by stress or anxiety?+
Yes — psychological stress can contribute to many physical symptoms, but organic causes should be excluded by a healthcare provider.
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