Is Social Security is for people who are ill and can not work?

I am seeking clarification..... My life long friend has a problem infection and has been operated on at least six times in thirty years. The infection never heals and ozzes puss almost daily. At least one day a week he spends the day soaking to relieve presure and release the puss. He is sore the few days prior and for a day afterwards. The jobs he has tried have not worked for him or the employer he is just not dependable. on a day when his puss is not running out his back side you would think he looks employable and he needs some money to get him by....What are his options?