A standard twin mattress is 39 by 75 inches. A king is 76 by 80 inches. This means that a headboard for a king bed is going to be about 76 inches or wider, plenty wide enough to go along the length of a twin bed. Headboards are often slightly wider than the bed for which they are made.
Hemoglobin, Hematocrit, Blood Count. In order to donate blood, a woman must have a hemoglobin level of at least 12.5 g/dL, and a man must have a hemoglobin level of at least 13.0 g/dL. For all donors, the hemoglobin level can be no greater than 20 g/dL.
You are not eligible to donate if you have AIDS or have tested positive for HIV. Back to Eligibility Guidelines. Hypertension (High Blood Pressure). If you are taking medication for this condition, you are generally eligible to donate depending on the severity of the condition.