The penis is a male organ that functions as a part of the reproductive and urinary systems. As a young man reaches puberty, the penis and testicles grow larger, and he begins to grow pubic hair. The size and shape of a penis varies between men. The size also varies between its flaccid and erect states. Although many men vary in size while flaccid, the difference in size is less in the erect state, according to the TeensHealth website. The majority of men fall into a normal range for penis size. Some, however, want to enlarge the length or girth.

1. Use a penis pump to maintain a larger-size penis during sexual activity. The penis pump can be helpful for a man who has undergone a prostate procedure, according to the Mayo Clinic. It can also help those who have had radiation therapy for prostate cancer. This treatment option has a low cost and does not require surgery.

2. Exercise to improve the appearance of the penis. Being in good physical shape improves the appearance of the body overall and increases self-esteem. As a man feels better about himself, he may become more sexually aroused and increase the size of an erect penis.

3. Lose weight to add length to the penis. Increased fat in the abdomen hangs over the pelvic region. The increased fat in the thighs also crowds the genitals. Obese men appear to have smaller penises because of the additional fat. Losing weight helps the penis appear larger, and it may gain length because the fat is not around the base of the penis.

4. Trim extraneous pubic hair, which can make the penis look shorter. The decreased hair may also help increase sensitivity at the base of the penis, according to the Mayo Clinic.

5. Get a reconstructive phalloplasty operation. Several types of surgical procedures can change the length or girth of the penis. To increase girth, a surgeon may place fat from another part of the body into the shaft of the penis. To increase length, the surgeon cuts the suspensory ligament, and this allows the penis to hang longer. Both procedures have risks, including infection and loss of sensation and normal function. Several medical organizations, including the American Urological Association and the Society of Plastic Surgeons do not endorse using penis surgeries for cosmetic reasons, according to the Mayo Clinic. Surgically inserting a penile implant can help a man suffering from erectile dysfunction increase size and sustain an erection.