
Credit to uncle google
1. Lack of exercise. Guys who tend to spend most of their youth in front of their laptop (or tend to do less sport) have higher possibility to get this abnormality.
2. Smoking. I do not smoke and i always hate the smell. Anyway! medical has proved that male who smoke more than 10 cigarettes in a day have the highest risk to get sexual dysfunction at the age of 40-ish.
3. Obesity or kegemukan - Those people who do not so sports and eat a lot or basically consume lots of calories a day will easily get this abnormality at the age of 40-ish. Remember a men's calories intake per day are only 2500 kcls.
p/s: the key is basically do not smoke, eat healthier by avoiding 2500 kcls intake daily and do exercise