What Is the Difference Between Bacteremia and Sepsis?

Bacteremia is a condition that results from bacteria entering the bloodstream. If enough bacteria are left untreated in the human body, it can lead to a severe reaction known as sepsis, according the Merck Manual Home Edition. Bacteremia and sepsis have a causal relationship, meaning one condition causes another. Sepsis is marked by fever, weakness, rapid heart rate, rapid breathing and a sudden increase of white blood cells.

The Merck Manual Home Edition also explains sepsis leads to septic shock, a condition that causes dangerously low blood pressure. Septic shock, if left untreated, causes organs and body functions to shut down due to blood loss. Sepsis and septic shock are life-threatening disorders.

Bacteremia is usually minor when small amounts of bacteria are naturally destroyed by the body's immune system. Tooth brushing, dental procedures, artificial joints, and infections such as pneumonia and urinary tract infections cause bacteremia, according to the Merck Manual. When enough bacteria survive in the bloodstream, they accumulate in tissues such as bones, joints, heart and brain. Bacteremia then becomes more serious.

Sepsis, followed by septic shock, usually occurs in people with already weakened immune systems. Sepsis is a systemic response to a runaway bacterial infection, meaning the entire body reacts. The first symptom of sepsis is usually fever, chills and weakness. The Merck Manual explains worsening symptoms include rapid heartbeat, rapid breathing, confusion and low blood pressure.