Common symptoms of lactic acid buildup in the legs include pain, soreness, and calf cramps. 1. Pain: It is the most obvious symptom of lactic acid buildup in legs. Lactic acid buildup is mostly due to long-term strain and exertion that produces local inflammation, leading to muscle soreness. This kind of pain usually lasts for a long time, and requires hot compresses and rest before it can be relieved. 2. Soreness: The accumulation of lactic acid in the leg muscles can stimulate the excitation of chemoreceptors in the muscles, and when the excitation is transmitted to the cerebral cortex, you will feel soreness. At the same time, due to the accumulation of lactic acid leads to the osmotic pressure of the muscle becomes larger, prompting the muscle tissue localized swelling, and then there is a soreness performance. 3. Cramps in the legs: Lactic acid buildup can cause partial loss of calcium ions in the legs, resulting in a lack of calcium, which can easily lead to cramps, accompanied by numbness and weakness in the legs. Lactic acid buildup in the legs is recommended to rest, and the symptoms can be improved through massage and physical therapy.