General medicine    The field of medicine concerned with primary care, e.g. family doctors, general practitioners.      Urology     Study of diseases of the kidneys, the urinary tract and the (male) reproductive organs. Urologists specialise in the diagnosis and treatment of prostate diseases, the treatment of erectile problems and male health in general.      Internal medicine    Speciality concerned with diseases of the internal organs. Internists usually specialise in diseases of a particular organ or organ system, e.g. the heart (cardiologists), the lungs (chest physicians) etc.      Endocrinology    Study of the hormone-producing organs and the hormones as well as hormone-related diseases.      Reproductive medicine    Study of human reproduction. Patients with infertility are referred to specialists in reproductive medicine.      Andrology     Study of the structure, function and diseases of the male reproductive organs. Andrologists often work in reproductive medicine. They treat male infertility and male health in general.