Cayenne pepper is one of the most common hot peppers used for flavoring foods and it is also a useful healing herb.  It has been used for thousands of years for healing a variety of health problems and modern medicine has verified it's effectiveness for many uses.   It is used for problems of the digestive system as well as heart and circulation problems.  A somewhat contradictory ability of cayenne is that, while it can aid circulation, it can also stop bleeding by aiding the clotting process.  
    For the digestive system, it aids in elimination, internal cleansing, and assimilation.  It helps the body rebuild stomach tissue damaged by ulcers or infections.  
    For the heart, cayenne can be given to a person having a heart attack and the attack usually stops within thirty seconds.  It can also help strengthen the heart.  It helps the circulatory system work better while also lowering blood pressure.  Most herbal mixtures sold to help blood pressure include cayenne or capsicum, the active ingredient in cayenne, as a primary ingredient.  
    Some other illnesses that may be helped by taking cayenne internally are headaches, sore throats, coughs, gout, and arthritis.  It can flush out the sinuses and remove excess mucus (I actually use a natural sinus spray that contains cayenne). 
    Externally, it can help psoriasis and many other itchy skin conditions.  It can also relieve muscle and joint pain.  When used externally, it is usually mixed with an oil such as olive oil.   I once read that rubbing a mixture of cayenne and olive oil on the stomach area would help burn off the spare tire.  I found that method ineffective and painful.  
Caution, both internally or externally, care must be taken not to use too much or it can burn.