Penile Thrush
Whether you refer to it as penile thrush, a yeast infection of the penis or male thrush, the end result is a painful penis. It is possible to can 'catch' a yeast infection of the penis through unprotected sex but then again you can be celibate and still develop penile thrush. Yeasts occur naturally in and on the body, but they only become a problem when they suddenly start to overgrow.
Yeasts like warm, moist places so around the groin and penis are ideal areas for them to live. If conditions become more favourable they will thrive and start spreading. There's usually no one thing that triggers off an attack, but anything that produces a prolonged increase in temperature and moisture in the groin area can be a potential problem. For example working out at the gym and not showering afterwards could act as a trigger. Also wearing tight jeans on a hot day will increase both the temperature and sweat levels in the groin area as well as create friction damage to the skin which the candida yeasts will take advantage of.
For the most part common sense and simple hygiene (that's a wash, DRY, and frequent change of underwear) will prevent most attacks but sometimes because you're feeling under the weather, you're taking antibiotics or you've spent 18 hours wearing tight PVC trousers on the hottest day of the year as a bet, an attack will occur. So what should you be looking for?
The most common symptoms are redness and raised spots on the head of the penis or on the foreskin. There may be a discharge and some material may collect under the foreskin which looks a bit like cottage cheese and has a yeasty smell. The skin can become very, very itchy and there maybe a painful burning sensation when you pee.
On the grounds that pictures can say so much more than words here is a link to some photos of penile thrush. Be warned that they are graphic and not for the squeamish. LINK.
If any of these symptoms appear, you should consult your doctor especially if you've never had them before to check that it is a yeast infection. Luckily penile thrush is a problem that can be effectively treated with anti-fungal creams or oral medication. So don't let embarrassment get in the way of treatment. If you don't do anything about it your penis could become inflamed and the thrush could spread into your groin.
If your partner has or has had a yeast infection it's a good idea for both of you to treat yourselves at the same time to prevent any chance of passing the infection back and forth.
If you're confident that you do have thrush and buy some over the counter medication read the instruction carefully. On the capsules it usually says something on the lines that if they haven't worked after 7 days see your doctor, if this is the case then you need to bite the bullet and make an appointment.