Drinking Water Before Bed and Overly Strong Air Conditioning Make the List! Doctor Reveals 'Top 10 Kidney-Damaging Habits,' With #1 Being Something Many Do Daily

Many people assume that being young and exercising regularly protects them from kidney disease, yet they overlook how daily bad habits may be quietly damaging their organs. A 45-year-old tech company executive, who regularly exercised, was alarmed to find reduced glomerular filtration rate (eGFR) and proteinuria during a health check-up. Nephrologist Dr. Hung Yung-Hsiang points out that most kidney diseases stem from long-term accumulation of unhealthy lifestyle habits and has compiled a special 'Top 10 Pre-Sleep Kidney-Damaging Behaviors' list to warn the public.

### 45-Year-Old Tech Executive Develops Proteinuria Despite Healthy Lifestyle: Doctor Lists 'Top 10 Pre-Sleep Kidney-Damaging Habits'

This 45-year-old tech executive, under high work stress, had the habit of lying in bed to handle emails and binge-watch shows after returning home. He often relaxed with whiskey and fried chicken as a late-night snack. Although he ran 5 kilometers every night, he frequently skipped rehydrating after sweating heavily and casually took painkillers whenever he had headaches.

It wasn’t until his health check-up revealed a drop in eGFR and the presence of proteinuria that he realized his kidneys were already in danger. Dr. Hung explained that all four of the executive’s daily habits fall into the category of pre-sleep kidney-damaging behaviors, showing that exercise alone cannot offset organ damage caused by poor lifestyle choices.

### Doctor’s 'Top 10 Pre-Sleep Kidney-Damaging Behaviors' List

Dr. Hung Yung-Hsiang shared the following 10 common pre-sleep bad habits on his Facebook fan page, urging the public to reflect on their lifestyle:

#### Rank 10: Burning cheap scented candles or incense for long periods in enclosed rooms

Burning low-quality aromatics in closed spaces produces PM2.5 and volatile organic compounds, triggering systemic chronic inflammation and oxidative stress, indirectly increasing kidney burden. It is recommended to maintain good ventilation.

#### Rank 9: Holding urine and not going to the bathroom

Occasionally holding urine won’t directly damage kidney function, but doing so long-term increases the risk of urinary tract infections. If bacteria travel upward to the kidneys, it could lead to pyelonephritis. Dr. Hung advises emptying the bladder before sleep. If you feel the urge to urinate before bed, go first—holding it can disrupt sleep quality or trigger infections.

#### Rank 8: Sleeping under excessively strong air conditioning

Dr. Hung notes many people set their AC extremely cold to fall asleep easily. While AC itself doesn’t directly harm kidneys, overly low room temperatures stimulate the sympathetic nervous system, causing blood vessel constriction and elevated blood pressure. Chronic sleep deprivation is a driver of hypertension and metabolic abnormalities, indirectly raising the risk of chronic kidney disease. It’s recommended to keep AC between 24°C and 26°C.

#### Rank 7: Taking cold showers before bed

Cold water stimulation causes blood vessel constriction and increased heart rate. For those with cardiovascular conditions or in a dehydrated state post-exercise, this can increase physical strain. To relax the mind and body before sleep, warm showers are recommended.

#### Rank 6: Engaging in intense exercise before bed without rehydration

High-intensity running or weight training right before bed, followed by heavy sweating without hydration, can easily lead to dehydration or even rhabdomyolysis. The released myoglobin can block renal tubules, causing acute kidney injury.

Dr. Hung points out that sports medicine literature confirms dehydration and rhabdomyolysis from intense exercise are among the main causes of acute kidney injury in young populations. He advises avoiding sudden extreme physical challenges before bed, ensuring timely hydration during exercise, and allowing sufficient recovery time.

#### Rank 5: Prolonged use of 3C devices delaying bedtime

Screen blue light suppresses melatonin secretion, leading to sleep deprivation. Disrupted circadian rhythms significantly increase the incidence of chronic kidney disease. It’s recommended to stay away from electronic devices 30 minutes before sleep, allowing the brain to calm down and transition into rest mode, which helps maintain stable blood pressure and protect the kidneys.

#### Rank 4: Chugging water or drinking strong tea/coffee before bed

Drinking large amounts of water before bed can cause nocturia, disrupting sleep; caffeine can make it hard to fall asleep, affecting metabolism and vascular health. Water should be replenished gradually throughout the day. If thirsty before bed, sip one or two small mouthfuls to moisten lips—do not chug water before bed under the guise of 'protecting your kidneys'.

#### Rank 3: Eating high-salt late-night snacks or strongly flavored foods

High-sodium foods like fried chicken, instant noodles, and braised dishes easily cause fluid retention and elevated blood pressure, increasing glomerular pressure and proteinuria output, accelerating kidney function deterioration.

#### Rank 2: Drinking alcohol before bed to fall asleep

Alcohol disrupts second-half sleep quality, increases nighttime urination, raises blood pressure, and heightens metabolic abnormality risks—delivering multiple blows to the kidneys.

#### Rank 1: Self-medicating with painkillers

The most common kidney trap. Randomly taking non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen reduces kidney blood flow. Combined with dehydration, this can easily trigger acute kidney injury. In elderly individuals or those with existing chronic kidney disease, it can rapidly lead to acute renal failure. According to the KDIGO Acute Kidney Injury Guidelines, NSAIDs are clearly identified as one of the primary clinical risk factors for drug-induced AKI. Dr. Hung advises that while painkillers aren’t forbidden, long-term self-purchasing and usage—or abusing them like supplements—must be avoided. Anyone with persistent pain should seek medical help promptly to identify the root cause.