What causes swollen lower legs upon waking up in the morning?

There are many causes of leg swelling upon waking in the morning, such as renal edema, cardiac edema, and hepatic edema, all of which can lead to swollen legs after getting up.

1. Renal Edema

Acute nephritis, chronic nephritis, or kidney disease can reduce renal blood flow, leading to sodium and water retention and excessive loss of protein in urine, resulting in edema. Under a doctor's guidance, diuretics such as furosemide, hydrochlorothiazide, and spironolactone may be used for treatment.

2. Cardiac Edema

This generally refers to edema caused by primary heart diseases. When cardiac function is impaired, it may lead to fluid accumulation, causing leg swelling upon waking. Treatment under medical supervision may include medications such as digoxin tablets or furosemide tablets.

3. Hepatic Edema

Decompensated liver disease may impair albumin synthesis, leading to hypoalbuminemia, reduced plasma colloid osmotic pressure, and formation of ascites, thus causing hepatic edema. Under a doctor’s guidance, furosemide and spironolactone may be used to alleviate symptoms of edema and ascites.

In addition, localized lower limb edema can also cause leg swelling upon waking. If this symptom persists over a long period, timely medical evaluation and treatment are necessary to avoid delaying diagnosis and management.