Complications of Acute Glomerulonephritis: What You Need to Know

Acute glomerulonephritis is a sudden inflammation of the glomeruli—tiny filters in the kidneys—often triggered by infections such as streptococcal bacteria. While many cases resolve on their own, untreated or severe forms can lead to serious complications affecting multiple organ systems. Understanding these potential risks is crucial for early detection and effective management.

1. Acute Left-Sided Heart Failure

Fluid overload is a hallmark of acute glomerulonephritis due to impaired kidney function. When the kidneys fail to excrete excess fluid, it accumulates in the bloodstream, increasing the volume the heart must pump. This added strain can trigger acute left-sided heart failure, particularly in individuals with pre-existing cardiovascular conditions.

Symptoms include severe shortness of breath, especially when lying flat (orthopnea), sudden nighttime breathlessness (paroxysmal nocturnal dyspnea), and noticeable peripheral edema. Immediate medical intervention, including diuretics and blood pressure control, is essential to reduce cardiac workload and prevent pulmonary congestion.

2. Hypertension and Hypertensive Emergencies

High blood pressure is a common consequence of acute glomerulonephritis. The condition activates the renin-angiotensin-aldosterone system (RAAS), leading to vasoconstriction and sodium retention. As a result, patients may develop sustained hypertension, which, if uncontrolled, can escalate into a hypertensive crisis.

Risks of Unmanaged Hypertension

Severe hypertension increases the risk of stroke, retinal damage, and further kidney injury. In children and young adults—who are frequently affected after a streptococcal infection—monitoring blood pressure is vital during recovery. Antihypertensive medications, such as ACE inhibitors or calcium channel blockers, are often prescribed to maintain safe levels.

3. Acute Kidney Injury (AKI)

One of the most direct complications is acute kidney injury, characterized by a rapid decline in renal function. Patients may exhibit elevated serum creatinine and blood urea nitrogen (BUN), reduced urine output (oliguria), and electrolyte imbalances such as hyperkalemia.

In severe cases, temporary dialysis may be required to manage fluid overload, correct metabolic acidosis, and remove toxins. Most patients recover kidney function over weeks to months, but timely supportive care is critical to prevent long-term damage.

4. Increased Susceptibility to Systemic Infections

Acute glomerulonephritis can compromise the body's immune defenses. Factors like proteinuria (loss of proteins in urine), malnutrition, and generalized inflammation weaken the immune system, making patients more vulnerable to secondary infections.

Common Infection Risks

These may include respiratory tract infections, urinary tract infections, or even sepsis in immunocompromised individuals. Preventive measures such as proper hygiene, vaccinations (e.g., pneumococcal and influenza vaccines), and nutritional support play a key role in reducing infection rates during recovery.

Early diagnosis, close monitoring, and multidisciplinary care—including nephrology, cardiology, and infectious disease specialists—are essential in managing complications and improving outcomes for patients with acute glomerulonephritis. Awareness and prompt treatment significantly reduce the risk of long-term morbidity.