Gynecomastia: This condition, characterized by the enlargement of breast tissue in men, is a common cause of nipple pain and can be associated with hormonal changes, certain medications, or other medical conditions. It's more prevalent in older men due to the natural decline in testosterone levels.

Ductal ectasia: A condition where the milk ducts in the breast become widened, leading to inflammation and potentially causing nipple pain. It's more common in older men and can be associated with periductal mastitis.
Periductal mastitis: Inflammation of the ducts under the nipple, which can cause nipple pain, discharge, and sometimes a mass. It's seen in both men and women but can be more noticeable in men due to less breast tissue.
Nipple dermatitis or eczema: Skin conditions that can cause itching, redness, and pain around the nipple area. In older men, skin conditions may become more prevalent due to decreased skin elasticity and potential allergies or sensitivities.

Breast cancer: Although rare in men, breast cancer can cause nipple pain, retraction, or discharge. It's crucial to investigate any new or persistent nipple symptoms in men, as male breast cancer tends to be diagnosed at a later stage.
Paget's disease of the breast: A rare form of breast cancer that starts on the skin of the nipple and extends to the areola. It can mimic eczema or dermatitis but is a serious condition requiring prompt diagnosis and treatment.

Sarcoidosis: A condition that can cause inflammation in various parts of the body, including the breast tissue, leading to nipple pain. It's less common but should be considered in patients with a history of sarcoidosis or other systemic symptoms.
Neurogenic nipple pain: Pain referred from other areas due to nerve issues, such as neuropathy or radiculopathy. This would be an unusual cause but could be considered if other diagnoses are ruled out and there's a history of neurological conditions.