Why is a person's left foot more likely to get sick than his right foot?

People's left foot is more likely to get sick than their right foot, because people's body is deficient in yin and yang. Where the body is weak, evil spirits will stagnate.

This is recorded in the Great Theory of Correspondence between Yin and Yang.

The sky is less than the northwest, so the northwest is cloudy, and people's right ear is not as bright as Zuo Ming. The land is not satisfied with the southeast, so the southeast is sunny, and people's left hand is not as strong as their right hand.

That is to say, the weather in the northwest is not enough, so it is cloudy in the northwest, and the eyes and ears on the right are not as bright as those on the left. The southeast is not full, so it belongs to the sun, and people are not as flexible on the left as on the right.

The East belongs to Yang, which is the essence gathered in the upper part. The first half is vigorous, and the second half is bound to be depressed. There will be situations where the ears are bright and the hands and feet are inconvenient. The west belongs to Yin, which is the essence gathered in the lower part. The second half is vigorous, and the first half is bound to be depressed. You are hard of hearing and can't see clearly, but your hands and feet are flexible and powerful. So it is also a feeling of exogenous evil. If it is in the upper part, the right side of the body is heavier. If it is in the lower part, the left side of the body is heavier. This is that the qi of yin and yang in heaven and earth cannot be biased, and the human body also has yin and yang deficiency. Where the body is weak, evil spirits will take advantage of it and stay there.