Cysts are air, gas, liquid or semisolid sacs that are not part of the normal tissue in the areas where they are located, notes MedicineNet. Abscesses are infected sacs filled with pus and debris that are warm and tender to the touch, states WebMD.
Cysts are common, vary in size and appear on or near the skin and on internal organs, explains MedicineNet. Cysts on or near the skin are generally noticeable and in some cases, such as in the breast or armpit areas, can be felt. Cysts on internal organs such as the liver are detected only through methods such as X-rays, ultrasounds and magnetic resonance imaging. While they are generally benign and dissipate on their own, in rare cases cysts are associated with cancer or serious infections that must be treated by a doctor.
Abscesses are usually surrounded by an area of pink or red skin and may appear externally or in the mouth, according to WebMD. Abscesses are caused when oil or sweat glands become blocked or when germs get under the skin or into glands, resulting in inflammation of the surrounding tissue. The pressure and inflammation from abscesses cause them to become painful until the abscess drains. Abscesses may open and drain themselves over time or doctors can drain them through incision. People with weakened immune systems due to conditions such as alcoholism and those who have suffered severe trauma or burns are more prone to abscesses.