Age

According to Marrow.org, potential donors must be between 18 and 60. MayoClinic.com says doctors make decisions on bone marrow donation to a relative on a case-by-case basis.

Weight

Your body mass index, or BMI, may determine your eligibility for donation. The registry cites safety concerns as the reason prospective donors usually must fall between the minimum and maximum weight limit for their height.

Restrictions

People with HIV, AIDS or other autoimmune disease cannot donate, reports Marrow.org. Bleeding problems such as hemophilia, or breathing problems, like asthma requiring the regular use of an inhaler, can also prevent donation. Tuberculosis, heart, kidney or liver disease, back problems or cancer may keep you from donating.

Illnesses and Lifestyle

Donors with allergies, diabetes, arthritis, depression, epilepsy, pregnancy and sexually transmitted diseases usually can donate. Individuals who travel often, have recently gotten a tattoo, piercing, immunization or had an infection are also eligible, says Marrow.org.

Considerations

MayoClinic.com says a doctor will evaluate you to confirm that donating bone marrow won't harm you or the recipient.

Source:

Marrow.org: Medical Guidelines for Joining the Registry

Mayo Clinic: Blood and Bone Marrow Donation

Community Blood Center: Donating Bone Marrow

More Information:

Be the Match Marrow Registry

CNN.com: Donating Bone Marrow, Saving Lives