DOMS is a result of muscle tissue breakdown during exercise. Although there are other theories (lactic acid accumulation or an inflammatory response of the body), the acute structural damage of muscle tissue is most likely. When we exercise, our muscles tissues are broken down. Once that occurs, DOMS will set in and last about 24-48 hours after exercise, depending on duration and intensity of the exercise(s) performed.
What are some ways you can help treat DOMS? While the only thing that really help with DOMS is recovery and not working the muscle group that is repairing for at least 48 hours, I would suggest using a foam roller to cool down after exercising. Massage therapy can also help with the discomfort and swelling of DOMS. Cryotherapy (ice packs and or ice bath) or homeopathy.