Is the penis only able to be lengthened and not thickened?

Patient's question:

Condition Description: Phimosis, Short penis. Erection less than 8 cm... Previous treatment history and effectiveness

Doctor's answer:

The size of an erect penis is entirely determined by the amount of blood flow to the corpus cavernosum, so the simplest way to increase penis size is to frequently train the penis to become erect, thereby increasing local blood flow. The principle is similar to bodybuilders, who train their muscles regularly, making them increasingly muscular.
The practice method involves gently massaging the penis daily during a shower or when you have free time. After it becomes erect, try to maintain firmness and erection without any stimulation. The key is to contract the anal muscles (Kegels) to make the blood flow last longer. Alternatively, during an erection, you can perform up-and-down jumps or left-and-right twisting movements (remember, you must not lose control and resort to masturbation!). With persistence, you will gradually notice your penis becoming thicker.
If you want more significant results, add 100 sit-ups daily, and you will find it truly effective.