Please see a professional surgeon or a Vascular surgeon who can help your friend.
Normally the blood in the leg veins follow the path of flowing from the feet right up to the heart. As this blood has to go against gravity, there are one way valves that prevent the blood from flowing back.
As age advances, if we stand for long hours, we all have a tendency to develop leaky valves which results in varicose veins. Commonly people have itching, some swelling and a bulge in the vein. If he has a bulge in the back of the knee, then it is referred to a varicose veins of the Short saphenous system.
In Mordern medical practice, the surgeons often ask for a scan to prove that patient has varicose veins, where and how bad is the issue etc.
After that depending on the patients condition they advise surgery. Radio frequency ablation is the current trend for treating varicose veins. But there are other simple methods like standard surgery still being offered to patients in hospitals who cannot afford the expensive treatment. You friend can think about it.
What he can do is.
1.Reduce weight if he is obese
2.Have good nutrition in terms of omega fatty and essential fatty acids that help in keeping the skin healthy. Because skin often gets damaged in long standing varicose veins.
3.If his job involves standing for many hours, he has to take a break, if possible lie down and raise his legs above the heart level for a few minutes, walk around and do repetitions of standing on the toes which helps the calf muscles of the leg to be active and this increases the sluggish flow in the leg veins.
4.He can use simple skin care moisturizing creams or pure coconut or olive oil that helps the skin to stay healthy.
5.Doctors also advise the use of compression socks, these are like regular socks but these exert more pressure and hence support the weak veins. Based on the actual extent, you friend would be advised the varicose vein stockings upto the knee level or upto the thigh level.
6.There are many products available that improve the tone of the skin, muscles and veins. These compounds include jojoba, sesame oil etc. There are Ayurveda and homeopathic products like Vein-Gard, Phyto-oils, Horse chestnuts extracts etc. Please consult the ayurvedic or homeopathic practitioners before you start on these. Allopathic doctors use Venusmin tablets to help with symptoms of varicose veins. Please do not self medicate.