Menopause: Given the patient's age, menopause is a common cause of flushing due to the decline in estrogen levels, leading to vasomotor symptoms such as hot flashes and night sweats.

Medication side effects: Various medications, including certain antidepressants, blood pressure medications, and hormones, can cause flushing as a side effect.
Anxiety or stress: Emotional distress can lead to flushing due to the body's "fight or flight" response, which increases blood flow to the skin.
Carcinoid syndrome: Although less common, carcinoid syndrome, often associated with neuroendocrine tumors, can cause flushing, especially if the tumor has metastasized to the liver.
Hypothyroidism: Some patients with hypothyroidism may experience flushing, among other symptoms like fatigue and weight gain.

Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic flushing, hypertension, and palpitations. Missing this diagnosis could be life-threatening due to the risk of hypertensive crises.
Thyroid storm: A life-threatening condition that occurs in patients with untreated or undertreated hyperthyroidism, characterized by severe flushing, fever, and tachycardia.
Medullary thyroid carcinoma: A type of thyroid cancer that can produce calcitonin, leading to flushing among other symptoms.

Mastocytosis: A condition characterized by the accumulation of mast cells in the skin and other organs, which can cause flushing, itching, and gastrointestinal symptoms.
Erythromelalgia: A disorder that causes burning pain, heat, and redness in the hands and feet, and can sometimes present with flushing.
Harlequin syndrome: A rare condition affecting the nerves that control blood flow to the skin, leading to asymmetric flushing and sweating.