Anemia was a blood disorder.
In 2268, Doctor Leonard McCoy commented that Hanar was a bit anemic, and blamed it on his consumption of food in pills rather than solid food. He gave the Kelvan a shot of what he deemed a "high-potency vitamin concentrate" and recommended he have three like it a day for the next few days. In reality, it was part of a ruse intended to distract Hanar and the rest of the Kelvans in order to seize the devices which had turned crew members of the USS Enterprise into solid blocks. (TOS: "By Any Other Name")