Can A kidney infection Kill You? & How Fast?

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As a nephrologist, A dealt with hundreds of serious kidney infections (complicated UTIs) in our nephrology ICU.

Complicated kidney infection is serious, especially in people with debilitating diseases or the elderly.

In this article, I will simplify all the facts and statistics about the possibilities and risk factors of life-threatening kidney infections.

Quick Insights:

A complicated kidney infection is serious, especially in people with debilitating diseases or the elderly.

Symptoms of a complicated urinary tract infection include fever, fast heartbeats, shortness of breath, confusion or disorientation, dizziness or lightheadedness, fainting attacks, chest pain, abdominal pain, decreased urine output, unusual sweating, cold, clammy, and pale skin.
Most kidney infections are not life-threatening, but if the bacteria or its toxins spread into the bloodstream (urosepsis), it can become life-threatening and could kill patients who are at risk.
In severe kidney infections that lead to the spread of infection into the bloodstream and different body systems, a septic shock could develop and kill the patients within a few days if not properly treated.

Risk factors for getting a serious kidney infection include stones in the urinary bladder, kidney, or ureter, obstruction inside the urinary tract, male gender, pregnancy, diabetes mellitus, chronic kidney disease, immunosuppressive medications, and patients with spinal cord or neurological diseases.

[1] What is a complicated kidney infection?

Urinary tract infections vary in severity, from simple urinary bladder infections (acute simple cystitis) to more serious kidney infections (pyelonephritis). It is called urosepsis if the infection spreads from the kidney to the bloodstream and other body organs.

Thankfully, most urinary tract infections are limited to the urinary bladder (cystitis). However, if the infection spreads beyond the urinary bladder, it is considered a “complicated urinary tract infection.”

When the infection spreads to the kidney or bloodstream, it is often accompanied by red-flag symptoms and signs (see the next section).

Acute simple cystitis usually does not lead to serious complications. In contrast, acute or chronic pyelonephritis tends to be more severe and may cause more serious symptoms or complications.

In conclusion, Urinary tract infections can be:

UTI type	Risk	Meaning (definition)
Acute Cystitis	Not serious	UTI that is confined to the urinary bladder (Commonest).
Acute pyelonephritis	Potentially serious	Infection that extends above the urinary bladder to the kidneys.
Urosepsis	Serious and may be life-threatening	The bacteria (or its toxins) causing UTI spreads to the blood and other organs.

[2] How do you know you have a serious kidney infection?

Simple urinary tract infections (acute cystitis) typically cause symptoms confined to the bladder and urine without systemic symptoms such as fever, chills, etc.

To make it simple, the table below illustrates the differences in symptoms between simple and serious (complicated) urinary tract infections.

Uncomplicated UTI symptoms	Complicated UTI symptoms
• Dysuria (pain during urination).
• Urinary frequency.
• Frequent waking up to pee at night (nocturia).
• Sudden urge to pee (urgency).
• Bladder pain (suprapubic pain).
• Blood in the urine (hematuria):
• Cloudy (turbid urine).	• All the classic symptoms of acute cystitis (dysuria, urgency, frequency, blood in urine, etc.).
• Fever >37.7°C (>99.9°F).
• Chills or rigors.
• Significant fatigue, muscle aches, or any other feature of systemic illness.
• Flank pain.
• Pelvic or perineal pain in men.
• Tenderness over the kidney area when your doctor examines it (A tender costovertebral angle at the upper back just below the ribs).

The bacteria causing severe urinary tract infections may spread into the blood and different body systems leading to sepsis (urosepsis) and septic shock symptoms such as:

Fever above 101°F (38.3°C) or a temperature below 96.8°F (36°C)
Fast heartbeats.
Shortness of breath and high breath rate.

Symptoms of UTI (complicated).
Confusion or disorientation
Dizziness or lightheadedness.

Fainting attacks.
Chest pain and a low oxygen saturation
Abdominal pain or discomfort

Decreased urine output
Unusual sweating
Cold, clammy, and pale skin.

[3] Can a complicated kidney infection kill you?

Most kidney infections are not life-threatening and aren’t going to threaten your life. However, if the bacteria or its toxins spread into the bloodstream (urosepsis), the condition may become life-threatening and could kill patients who are at risk.

The most common bacterial cause of UTI is E. Coli. Alone, it causes more than 70% of the causes. E. coli is becoming more treatment-resistant nowadays and causes complicated kidney infections.

One study found that the chance of death caused by urosepsis secondary to E. Coli is about 6.3% to 12.7%, depending on several factors such as the resistance of the bacteria to antibiotics, the patient’s age, and other co-existing diseases.

[4] How fast can a kidney infection kill you?

A simple urinary tract infection (acute cystitis) is typically not serious or life-threatening unless it spreads to the kidneys or the blood leading to sepsis and septic shock.

In severe kidney infections that lead to the spread of infection into the bloodstream and different body systems, a septic shock could develop and kill the patients within a few days if not properly treated.

So, it is important to beware of the following:

The signs and symptoms of a complicated kidney infection and sepsis (see section 2).
The risk factors for getting a life-threatening kidney infection (see the below section).

From my own practice in our nephrology ICU, Most cases of urosepsis respond to proper treatment (typically intravenous, powerful antibiotics). However, a small percentage (5% to 15%) may die from serious kidney infections in a few days to weeks.

[5] Risk factors of getting a serious kidney infection.

The following groups are at higher risk of developing complicated UTIs when they catch an infection.

Presence of Stones in the Urinary bladder, kidney, or ureter.
Obstruction inside the urinary tract (commonly ureteric, caused by a stone or a structure).