Nuclear fusion (E Teller) : Two lighter nuclei has fused to form heavier nuclei at high temperature and pressure. They are also called thermonuclear reations due to the high temperature required (~10^8 C). First an Atom bomb is exploded to create the conditions for fusion in which Dueterium nuclei are fused to form Helium with the release of tremendous amount of energy.

USA has tested 60 Mt (having 60,000,000 tons of TNT's explosive power) fusion bomb. (1 ton = 1000 kg)

Radiation sickness : During nuclear explosion, radiations are emitted and can cause radiation sickness. Symptoms include nausea, vomiting, loss of hair & appetite. More radiation dose can cause destruction of bone marrow and thus leading to blood cancer (lukemia). The most sensitve part of the body to radiation are testes (genital tissues), bone marrow, ovary, skin,
liver and kidney.