A lump in the right breast of a man may be painful when pressed because of breast development, chest folliculitis and male breast cancer. 1. Mammary gland development: male breasts usually do not have breast tissue, when male patients have enlarged and hyperplasia of breast gland ducts, similar to female breast hyperplasia, patients can feel a lump in the breast, accompanied by pressing pain. 2. Chest folliculitis: due to male skin oil secretion is more exuberant, do not pay attention to local hygiene, resulting in chest pore clogging, triggering folliculitis, the chest will appear small hard lumps and pressure pain phenomenon. 3. Male Breast Cancer: Breast cancer is highly prevalent in women, but with congenital heredity, obesity or impaired liver function, breast cancer may also appear, accompanied by the symptom of lump and pain when pressed. When patients have right breast lump pressure pain, they should promptly seek medical treatment under the guidance and advice of doctors