Kidney cancer often develops silently, with initial symptoms so vague they're easily mistaken for common health issues. Aches, pains, and fatigue are often attributed to everyday stress. However, these seemingly harmless symptoms can sometimes indicate a more serious condition, especially kidney cancer.

Here are 7 early kidney cancer symptoms that are frequently overlooked:

Blood in urine

Blood in the urine is often mistaken for a urinary tract infection or kidney stones. It's particularly easy to miss if the blood isn't visible (microscopic hematuria). According to the American Cancer Society, this is one of the most common early signs, yet it's often overlooked.

Persistent pain in the flank or lower back

Kidney cancer can cause a dull, persistent ache in the flank or lower back, just below the ribs. This pain doesn't lessen with rest or changes in position, unlike typical muscle pain. Early-stage kidney tumors can press on surrounding tissues, causing this type of pain.

Unexplained weight loss

Sudden weight loss, especially without dieting or exercise, can be a sign of a serious medical condition. In kidney cancer, the body's metabolism changes due to inflammation and cancer-related factors, causing fat and muscle loss.

Unexplained weight loss is a red flag in many cancers, including renal cell carcinoma.

Illustration of a healthy kidney in a normal person. Image: KUMC

Illustration of a healthy kidney in a normal person. Image: KUMC

Persistent low-grade fever without infection

Kidney cancer, especially in its early stages, can cause a recurring low-grade fever. This happens due to the immune system's response to the growing tumor.

This symptom is easily dismissed because it's not accompanied by a cough, congestion, or infection, just a general feeling of warmth, fatigue, and vague discomfort.

Prolonged fatigue

Fatigue from kidney cancer differs from ordinary tiredness. It's a deep exhaustion that doesn't improve with rest.

The cause may be anemia, which occurs when the kidney's ability to produce erythropoietin (a hormone involved in red blood cell production) is affected by the tumor. This leads to reduced oxygen supply to the body, causing severe fatigue.

Swelling or a lump in the abdomen or flank

A kidney cancer tumor can form a hard, immobile lump in the flank or lower back. Initially, the lump may be painless and easily mistaken for weight gain or bloating. In some cases, swelling only appears when the tumor grows large enough to press outward.

Night sweats

Kidney cancer can cause systemic inflammation, leading to excessive sweating during sleep. Night sweats aren't just mild; they can be so intense that they require changing clothes or bedsheets. It's the body's way of trying to regulate internal imbalances, even before more obvious signs appear.

My Y (Times of India)