In Ayurveda, dhatu refers to the bodily tissues that cause the various organs and systems to function, and provide structure to the body. The dhatus are built sequentially so each dhatu is created out of the previous one. They get their nourishment from the nutrients produced by the digestive system.
The formation of the dhatus is due to the catalysts that transform one tissue into another. The process of metabolism is purely based on synchronizing the tissues in perfect harmony so they can carry out their respective physiological functions.
The word dhatu stems from its Sanskrit root Daa meaning ‘support’ or ‘that which bears’. This is why dhatus are the foundation of development and survival. According to Ayurveda, there are seven primary types of dhatus or tissues in the human body. These dhatus are made up of the five great elements or panch mahabhutas – Ether, Air, Fire, Water and Earth.
These dhatus should always be balanced for the human body to be healthy. Any imbalance in the dhatus can cause ailments or diseases. The seven dhatus are as follows:
The Sanskrit word rasa translates to ‘sap’ or ‘juice’. This is the lymphatic fluid and plasma. The principle role of plasma is to nourish the body and strengthen rakta (blood). The supporting tissues where we find rasa are breast milk and menstrual blood.
Rakta is formed by the metabolism of rasa dhatu. The main role of blood is to nourish the body and preserve life.
This tissue is formed from the previous tissues – plasma and blood. The mansa dhatu are the muscles that cover the bone and provide shape to the body.
Medha dhatu is the fatty tissue that is a part of the muscular tissue. Their role is to keep the various organs lubricated and to maintain homeostasis (optimum internal temperature).
Asthi or bones are the finer product of the fatty tissues, which form the most solid member of the dhatus. They are the basis of the structure of the human body.
A derivative of the bone tissue, it is a yellow-red substance. It is semi-solid and is present as a filling within the bones. Majja dhatu is also found within the brain and the spine.
A product of the extreme refinement of the bone marrow, shukra dhatu is the source of vitality and energy. It is responsible for ojas, the energy that is the fine essence of all the seven dhatus.