1. Redness and warmth in the legs: Decreased blood flow from the heart to the legs can cause increased vein pressure, resulting in redness and warmth. 

2. Swelling in one arm or leg: Blood clots can impede blood flow back to the heart, causing increased pressure and swelling, usually on one side only. 

3. Intermittent claudication: Blocked blood vessels in the legs can lead to pain during walking or exercise, which may subside with rest but return upon activity. 

4. Pain in one arm or leg: Inflammation in the limbs caused by blood clots can result in aching and discomfort. The pain may start mild but worsen over time. 

5. Weakness in the hands and feet: Unexplained fatigue in the hands and feet, difficulty lifting one side of the body, sudden unsteadiness, or falls while walking should raise concerns about blood clots.