Recently I’ve had quite a few people complain to me that they have an annoying boil. I went for decades without experiencing one but in the past few years have had one or two. I attributed it to me getting too hot and my skin not being able to breathe. In one sense that is true but I discovered the real culprit is bacteria -more precisely it’s Staphylococcus aureus.Staph bacteria live on the surface of our skin. They don’t pose a problem there but they do when they get inside the body. And that can be an easy feat for them. A cut or scrape on the skin provides them ready access to get under our skin, into the bloodstream and cause infection.When they infect a hair follicle or a few hair follicles, a boil may appear. The boil is the result of the body’s natural defence response to the infection. When staph bacteria infect a hair follicle, specialised white blood cells called neutrophils rush to the site to fight them off. This action leads to inflammation. The skin usually becomes a raised red lump. It can be painful and when it isn’t the area is often tender if touched.As the work of the neutrophils progresses, pus — a mixture of old white blood cells, bacteria and dead skin cells, forms under the skin. At this stage it is often tempting to simply squeeze the pus out. Doing so usually alleviates the pain but can also cause the infection to spread if not done carefully.Boils become pus filled quickly and the longer they are left, the larger they become until eventually they rupture and drain.You can usually care for a single boil at home, but should call your doctor if it is extremely painful, lasts longer than two weeks or occurs with a fever.A carbuncle is a group of boils and often requires medical attention as the infection goes deeper. They develop and heal more slowly than boils and usually leave a scar. Symptoms tend to be more severe than with a single boil and can include a general unwell feeling, chills and fever.Because they are essentially an infection of the hair follicle, boils develop in the hairy areas of the body. Areas prone to sweat and/or friction, like the armpits, thighs groin and buttocks are the most common sites but they also form on the face and neck.While healthy people can develop a boil, the following factors can make you more susceptible: skin problems like eczema and acne where the protective barrier of the skin is compromised; direct contact with another person’s boil; low immunity, MRSA and blood poisoning — where bacteria from your boil gets into your bloodstream and causes infection elsewhere in your body. This is called sepsis and can be serious causing conditions like endocarditis (infection of the heart) and osteomyelitis (bone infection). Sepsis can lead to septic shock where the body’s blood pressure becomes so low that it can cause death.Although it’s possible that a boil could lead to death, most times it’s easy to treat small ones at home without the aid of a physician. Applying a warm compress to the boil often relieves the pain and promotes the natural drainage process. A compress soaked in warm salted water will help the boil to rupture more quickly. Apply the compress to the affected area for at least ten minutes every few hours.It is important to wash your hands thoroughly and launder clothing, compresses and other items that have come into contact with the infected area.If you are not allergic, tea tree oil may help treat a boil and can also be added to the water used to wash infected articles. Tea tree oil has antiseptic, antibiotic and antifungal properties.If you have a large boil or a carbuncle, you may need a doctor to treat the problem. You should never try to lance a boil yourself, as this is likely to spread the infection. If the infection is deep your physician may have to pack the area with sterile gauze so that all the pus can drain out.