Viagra (pharmacological name is sildenafil citrate) is produced in the form of blue pills and can be of 25, 50 and 100 mg to treat such a common disorder in men as erectile dysfunction. The erectile dysfunction can be caused by various factors, some of which are of psychological nature, while others are based on physical and health problems. A lot of men suffer from inability to get or maintain erection strong enough for sexual intercourse. At the same time, there are also healthy men who face this problem from time to time. It can be because of hard working, stress or other reasons. This is where Viagra can be irreplaceable. Problems with impotence can be prevented, but if they already occurred, don't panic, fortunately, it can be helped. Viagra is a very popular treatment of ED which is always available. You can also find the generic Viagra at your place. Although, this medicine is proved to be safe for health, there still can be some insignificant side effects. Viagra may cause such symptoms as upset stomach, headache, facial flushing and more rarely, sensitivity to light, bluish and blurred vision. Viagra can be not recommended to some men, that is why you should firstly discuss your health state with your doctor and get the prescription with the right dosage.