Staph infections can range from minor skin problems to endocarditis, a life-threatening infection of the inner lining of your heart (endocardium). As a result, signs and symptoms of staph infections vary widely, depending on the location and severity of the infection.

Skin infections

Skin infections caused by staph bacteria include:

• Boils. The most common type of staph infection is the boil, a pocket of pus that develops in a hair follicle or oil gland. The skin over the infected area usually becomes red and swollen.

If a boil breaks open, it will probably drain pus. Boils occur most often under the arms or around the groin or buttocks.

• Impetigo. This contagious, often painful rash can be caused by staph bacteria. Impetigo usually features large blisters that may ooze fluid and develop a honey-colored crust.
• Cellulitis. Cellulitis — an infection of the deeper layers of skin — causes skin redness and swelling on the surface of your skin. Sores (ulcers) or areas of oozing discharge may develop, too.
• Staphylococcal scalded skin syndrome. Toxins produced as a result of a staph infection may lead to staphylococcal scalded skin syndrome. Affecting mostly babies and children, this condition features fever, a rash and sometimes blisters. When the blisters break, the top layer of skin comes off — leaving a red, raw surface that looks like a burn.

Food poisoning

Staph bacteria are one of the most common causes of food poisoning. Symptoms come on quickly, usually within hours of eating a contaminated food. Symptoms usually disappear quickly, too, often lasting just half a day.

A staph infection in food usually doesn't cause a fever. Signs and symptoms you can expect with this type of staph infection include:

• Nausea and vomiting
• Diarrhea
• Dehydration
• Low blood pressure

Septicemia

Also known as blood poisoning, septicemia occurs when staph bacteria enter a person's bloodstream. A fever and low blood pressure are signs of septicemia. The bacteria can travel to locations deep within your body, to produce infections affecting:

• Internal organs, such as your brain, heart or lungs
• Bones and muscles
• Surgically implanted devices, such as artificial joints or cardiac pacemakers

Toxic shock syndrome

This life-threatening condition results from toxins produced by some strains of staph bacteria and has been linked to certain types of tampons, skin wounds and surgery. It usually develops suddenly with:

• A high fever
• Nausea and vomiting
• A rash on your palms and soles that resembles sunburn
• Confusion
• Muscle aches
• Diarrhea
• Abdominal pain

Septic arthritis

Septic arthritis is often caused by a staph infection. The bacteria often target the knees, shoulders, hips, and fingers or toes. Signs and symptoms may include:

• Joint swelling
• Severe pain in the affected joint
• Fever

Many people carry staph bacteria and never develop staph infections. However, if you develop a staph infection, there's a good chance that it's from bacteria you've been carrying around for some time.

These bacteria can also be transmitted from person to person. Because staph bacteria are so hardy, they can live on inanimate objects such as pillowcases or towels long enough to transfer to the next person who touches them.

Staph bacteria are able to survive:

• Drying
• Extremes of temperature
• Stomach acid
• High levels of salt

A variety of factors — including the status of your immune system to the types of sports you play — can increase your risk of developing staph infections.

Underlying health conditions

Certain disorders or the medications used to treat them can make you more susceptible to staph infections. People who may be more likely to get a staph infection include those with:

• Diabetes who use insulin
• HIV/AIDS
• Kidney failure requiring dialysis
• Weakened immune systems — either from a disease or medications that suppress the immune system
• Cancer, especially those who are undergoing chemotherapy or radiation
• Skin damage from conditions such as eczema, insect bites or minor trauma that opens the skin
• Respiratory illness, such as cystic fibrosis or emphysema

Current or recent hospitalization

Despite vigorous attempts to eradicate them, staph bacteria remain present in hospitals, where they attack the most vulnerable, including people with:

• Weakened immune systems
• Burns
• Surgical wounds

Invasive devices

Staph bacteria can travel along the medical tubing that connects the outside world with your internal organs. Examples include:

• Dialysis tubing
• Urinary catheters
• Feeding tubes
• Breathing tubes
• Intravascular catheters

Contact sports

Staph bacteria can spread easily through cuts, abrasions and skin-to-skin contact. Staph infections may also spread in the locker room through shared razors, towels, uniforms or equipment.

Unsanitary food preparation

Food handlers who don't properly wash their hands can transfer staph from their skin to the food they're preparing. Foods that are contaminated with staph look and taste normal.

If staph bacteria invade your bloodstream, you may develop a type of infection that affects your entire body. Called sepsis, this infection can lead to septic shock — a life-threatening episode with extremely low blood pressure.