Polycystic Ovary Syndrome (PCOS): This condition is characterized by weight gain, acne, and hormonal imbalances, which could lead to palpitations and sweating due to potential insulin resistance and metabolic syndrome. The use of a cane might be less directly related but could be due to mobility issues secondary to weight gain or other associated conditions like osteoarthritis.

Hypothyroidism: Weight gain, sweating, and palpitations can be symptoms of hypothyroidism. Acne is less common but can occur, especially if there's an associated hormonal imbalance. The use of a cane could be related to muscle weakness or joint pain associated with hypothyroidism.
Cushing's Syndrome: This rare endocrine disorder is caused by excess cortisol and can lead to weight gain, acne, and potentially palpitations and sweating due to the metabolic effects of cortisol. Mobility issues leading to cane use could result from muscle weakness.
Diabetes Mellitus Type 2: Although less common in a 29-year-old without other risk factors, type 2 diabetes can cause weight gain, sweating, and palpitations due to hyperglycemia and potential cardiac effects. Acne can be associated with insulin resistance, and mobility issues could arise from neuropathy or other complications.

Pheochromocytoma: A rare tumor of the adrenal gland that causes excess adrenaline, leading to palpitations, sweating, and potentially weight gain and acne due to metabolic effects. Although rare, missing this diagnosis could be fatal due to the risk of hypertensive crises.
Hyperthyroidism: Can cause weight gain, palpitations, sweating, and potentially acne. The use of a cane might be less directly related but could occur due to muscle weakness or osteoporosis secondary to hyperthyroidism. Missing this diagnosis could lead to significant morbidity, including thyroid storm.
Cardiac Conditions (e.g., Arrhythmias, Cardiomyopathy): These could cause palpitations and potentially sweating and weight gain if there's associated heart failure. Acne and cane use might be less directly related but could occur in the context of overall decreased mobility and health.

Acromegaly: A disorder caused by excess growth hormone, leading to weight gain, sweating, and potentially palpitations and acne. Mobility issues could result from joint problems or carpal tunnel syndrome associated with acromegaly.
Congenital Adrenal Hyperplasia (CAH): A group of inherited disorders that affect the adrenal glands, potentially leading to an imbalance of sexual hormones and cortisol, which could cause acne, weight gain, and potentially palpitations and sweating.
Thyroid Storm: A life-threatening complication of untreated or undertreated hyperthyroidism, which could present with weight loss (though weight gain might precede this in some cases), palpitations, sweating, and potentially acne due to the extreme metabolic state.