Well, it would depend on what's causing the yeast infection. If you are sexually active, it can be sexually transmitted, it can come from taking antibiotics, from douching, using perfumes or chemicals in your genital area, too tight clothes or underwear, birth control pills, diabetes, or other infections. Once you figure out the cause then you can figure out how to prevent it from coming back.
Keep your clothing and underwear clean, cool, dry, loose fitting, natural fibers. No douching, or creams, sprays, lotions, harsh or scented soaps in the genital area. Be sure to dry well after swimming, baths or showers. Eat yogurt that says on the container "contains live active cultures".
With the chest cold, same thing. Before you can cure it you have to find out what's causing it. Smoking flu cold, virus, emphysema, all can cause coughing. It sounds like you might need to see your doctor for a full checkup.
Let me know if you have any other questions or want to talk more.
Chase
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