Any factor that aid in growth of candida fungus by providing ideal conditions in moist parts of body cause yeast infection. Following are some of the common causes of yeast infection: 

• Excessive sweating: Sweating is good for maintaining our body temperature. But it also makes it difficult to keep yourself hygienic. In physically active people who cannot keep themselves clean due to their nature of work and environment yeast infection is common. Areas like underarms, groins etc. are susceptible to get infected easily.
• Tight clothing: Wearing tight clothing which restricts free air flow cause inhibition in skin breathing. Some clothing like thongs etc do not absorb sweat properly so keep the skin wet. Such skin condition is ideal for yeasts to cause infection. Always try to wear cotton next to skin which not only absorbs sweat but also allow skin to breath properly.
• Diapers: Usually it is not possible to change diapers immediately after baby urinates. This leaves soft tender baby skin wet in contact with acidic urine. If diaper is tight it also restricts fresh air. Under such environment yeasts take over and multiply their numbers rapidly causing infections.
• Poor Cleaning Habits: Unhygienic moist environment is ideal for yeast growth. Not brushing properly or chewing tobacco etc increases risk of getting affected oral yeast infection considerably.
• Pregnancy: During pregnancy woman’s body goes through several complex hormonal changes. This mostly aids in getting affected with vaginal yeast infection.
• Using Antibiotics: Yeast infection is also caused as side effect to certain medications like antibiotics and steroids etc.
• Poor Diet: Well balanced nutritious diet can keep several infections and disorders miles away from our body. If body does not receive all required nutrients in proportionate quantities it is prone to get infected easily.

 As you can see from above points, most of the causes of yeast infection can be avoided if you can take little extra effort. By taking little more care of yourself in day to day life and ensuring healthy lifestyle in eating, clothing and other activities you can drastically reduce the risk of getting affected with several diseases, yeast infection is just once among them.