Dhatwagni means agni related to tissues. These are the factors of agni related to metabolism other than digestion. There are seven tissues in the body as per Ayurveda, so seven dhtwagnis as well. Seven dhatus (tissues) in the body are rasa (plasma), rakta (blood), mamsa (muscle), medas (fat), asthi (bone), majja (bone marrow) and sukla (reproductive tissue). The seven dhatwagnis act on the respective dhatus (tissue) and are responsible for healthy tissues.