Individuals who have completely recovered from a bout of mononucleosis and exhibit no signs of jaundice are eligible to donate blood, according to the Community Blood Center. The American Red Cross explains that individuals who developed hepatitis caused by a virus after age 11 are not eligible to donate blood.
Individuals with illnesses such as lung disease, sickle cell anemia and liver disease are also ineligible to donate blood, according to Mississippi Blood Services. Additional disqualifying factors include heart disease, blood diseases and pregnancy. Individuals who donate whole blood can only do so every 56 days. Individuals who donate blood platelets can give blood once every three days.