The word dhatu comes from the root DHA meaning basis or foundation. The purpose of metabolism is to create proper dhatus together with the intelligence with which they carry out their role as the field of physiological activity. Dhatus are created through the action of catalysts that convert one tissue to another. In this way, progressively refined tissues are created from their grosser precursors. The catalyst for this is another type of agni, a dhatu-agni or metabolic fire. According to Ayurveda dhatus are the basic tissues, which maintain and nourish the body in other words it can be defined as one, which supports the body. There are mainly seven types of dhatu according to Ayurveda. The seven dhatus are composed of five mahabhutas. These dhatus remain inside the human body in a proper equilibrium so that the body can function properly but any disturbance in their equilibrium causes disease.
Dhatus are the main constitution of the body. According to Ayurveda there are seven tissue systems (dhatus) in the human body. These dhatus are responsible for keeping the body in a shape while providing support to the body as well as the mind. The word dhatu is derived from the Sanskrit word dha that means “to put or place”. They are known as the root principles of the body. Each tissue is controlled by one of the three elements. It is considered as the element that constructs the body. These elements form the pillars of the body that further forms the basis of nourishment and growth. The dhatus take different forms in the human body in order to maintain life.
These seven tissues (dhatus) are :
Rasa dhatu (fluid/Plasma)
Rakta dhatu (blood)
Masma dhatu (muscle)
Meda dhatu (fat)
Ashti dhatu (bone)
Majja dhatu (Bone marrow)
Shukra dhatu (reproductive fluid or semen)
The rasa dhatu is derived from the digested food. It provides nourishment to each and every cell and tissue of the body. It is considered as similar to plasma.
The rakta dhatu is considered as the basis of life. It provides vitality and colour to the body. It is similar to the circulating blood cells. The masma dhatu is derived form the blood and is responsible for providing physical strength to the body. Meda dhatu is derived from the muscle or masma dhatu. It consists of adipose tissue, provides energy and lubricates the body. Ashti dhatu consists of bones tissues including the cartilages. Its main function is to provide support to the muscle tissues. Majja dhatu denoted the tissue of yellow and red bone marrow. Its main function is to provide viscidity to the body. The shukra dhatu is derived from the core of majja. The main function of this reproductive tissue is to help in the process of reproduction, provided satisfaction and strengthens the body.
According to the concept of Ayurveda shukra is the most important dhatu among all the others. It states that one needs a hundred drops of blood to produce one drop of semen. It is the soul of all the other body tissues as it has the capacity of producing new life.
Each dhatu is developed from the layer of previous tissue, starting from the rasa (fluid) dhatu. If the first layer is unhealthy, all the other layers get infected causing various health problems. Each organ and body systems are made up of the tissues or dhatus. Each dhatu has its own metabolism or Agni. The metabolism of rasa dhatus converts the digested food into the energy. Every dhatu acts as a precursor of the next dhatu. Fluid or plasma is transformed into blood, blood prepares muscles, muscles produces fat, fat is further used to make bones, bones forms marrow and marrow ultimately produces semen and reproductive system.
Dhatus are responsible for the immune mechanism of the human body. In case of wasting of dhatus, the body construction collapses leading to the end of life. Any kind of imbalance in the tridoshas affects the dhatus as doshas influenced the dhatus. This imbalance results in many disorders in different dhatus.
Rakta dhatu – loss of luster and cracks.
Masma dhatu – joints cracking and eye problems.
Meda dhatu – hair problem, loose joints, thin body constitution and teeth and nail problems.
Asthi dhatu – dry mouth, general weakness, bone diseases, lightness and thinness.
Majja dhatu – lassitude.
Shukra dhatu- impotence, non- ejaculation of semen and exertion.
Ayurveda uses various therapies to balance the seven tissues by reducing the excessive elements and increasing the deficient ones. These can be balanced by the use of herbs, natural foods and variations in lifestyle.