what causes septic shock

Septic shock is usually caused by a severe infection that triggers an extreme body-wide inflammatory response, which drops blood pressure and reduces blood flow to vital organs. It is most often linked to bacterial infections, but fungi and, rarely, viruses can also be involved.

What happens

An infection can start in the lungs, urinary tract, abdomen, skin, or bloodstream, then spread enough to overwhelm the immune system. The body’s inflammatory chemicals can make blood vessels widen and become leaky, which causes dangerously low blood pressure and poor organ perfusion.

Common causes

• Bacterial infections are the most common cause.

• Gram-positive and gram-negative bacteria are both important causes.

• Fungal infections can also cause septic shock.

• Infections related to indwelling devices like IV lines or urinary catheters can be a trigger.

Who is at higher risk

Risk is higher in older adults, very young children, people with weakened immune systems, and those with conditions like diabetes, cancer, or chronic kidney/liver disease. Recent hospitalization, major surgery, burns, trauma, and indwelling catheters also increase risk.

When to get urgent help

Septic shock is a medical emergency. If someone has a suspected infection plus confusion, very low blood pressure, trouble breathing, extreme weakness, or reduced urine output, they need immediate emergency care.

If you want, I can also give you a simple “sepsis vs septic shock” breakdown.