Visible veins are often harmless, linked to aging, low body fat, or exercise. But sudden or unusual vein changes can signal serious health problems. Here are five conditions to watch for:

1. Chronic Venous Insufficiency (CVI)**
CVI occurs when vein valves weaken, causing blood to pool in the limbs. “Visible, rope-like veins,” leg swelling, and skin discoloration are signs. It’s common in older adults or those who sit or stand for long periods. Left untreated, it may lead to leg ulcers or blood clots.

2. Varicose Veins**
These appear as “dark blue or purple veins that are raised or bulging,” usually in the legs. Though often seen as cosmetic, they may indicate deeper vein issues. Risk factors include genetics, pregnancy, obesity, and prolonged standing.

3. Deep Vein Thrombosis (DVT)**
DVT is a dangerous clot in a deep vein, often causing “sudden swelling,” pain, and warm, red skin. It can lead to a pulmonary embolism, so immediate treatment is crucial.

4. Congestive Heart Failure (CHF)**
When the heart weakens, blood backs up in veins, making them more visible. Look for fatigue, shortness of breath, and swelling in extremities.

5. Peripheral Vascular Disease (PVD)**
PVD narrows blood vessels, causing tired legs, numbness, and slow-healing wounds.

If one limb suddenly shows more visible veins, or if veins become painful or discolored, seek medical help.