Symptoms of low testosterone levels in adult men may indicate male hypogonadism. This condition occurs when a man's body does not produce enough testosterone hormone. According to MayoClinic.com, adult men with low testosterone levels may experience physical, reproductive and psychological changes.
Erectile Dysfunction
According to MayoClinic.com, adult men with low testosterone levels may experience erectile dysfunction. Men with this condition may not attain or keep a penile erection firm enough for sexual intercourse, reports The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
Infertility
Men with low testosterone levels may experience infertility. According to the Shared Journey website, testosterone is necessary for a man's reproductive system to function well. The Shared Journey site suggests that men who are infertile should undergo testing for testosterone deficiency.
Less Hair
Lower beard and body hair growth are a symptom of testosterone deficiency. According to the Merck Manuals Online Medical Library, a testosterone-deficient man may not have body hair or have only sparse pubic and auxiliary body hair.
Muscle Mass Reduction
Muscle mass reduction may occur in men with low testosterone levels. According to an April 2008 article in the American Geriatric Society's "Clinical Geriatrics," men with low testosterone levels may experience lean muscle mass reduction and abdominal weight gain.
Gynecomastia
Men with low testosterone levels may develop gynecomastia. According to MedlinePlus, men with gynecomastia develop abnormally large breasts. Gynecomastia may occur in either one or both breasts, and breasts often enlarge unevenly. Gynecomastia is normal during male puberty but subsides after several months.
Osteoporosis
Osteoporosis may accompany low testosterone levels in men. Osteoporosis weakens bones and increases the risk of fracture. According to Clinical Geriatrics, osteoporosis may progress painlessly until a fracture occurs. Common fractures occur in the hip, spine and wrist.
Psychological Problems
Men with low testosterone levels may experience fatigue, difficulty concentrating or a lower sex drive, reports MayoClinic.com. According to an ABC 7 News Chicago interview with urologist Dr. Robert Brannigan, depression can accompany low testosterone levels, and some testosterone-deficient men are mistakenly treated with antidepressants.
