| Name | Description | 
  | Harvester Infection [1] | Harvesters are a form of nanobiogenic weapon, developed by the T'Lani and the Kellerun during their war. Once infected death follows in the next 24-48 hours. [1] | 
  | Heartburn [2] | Burning sensation in the chest caused by indigestion. [2] | 
  | Hemocythemia [3] | Condition in which intracellular pressure is unstable. This condition is also called Hemocythemic imbalance. It is treated with osmotic pressure therapy. [3] | 
  | Hesperan Thumping Cough [4] | A flu-like infection. [4] | 
  | HTDS [5] | Holotransference Dementia Syndrome. A syndrome in which a person becomes so involved in a holo program that they lose their sense of identity. [5] | 
  | Hypochondria [6] | Condition which causes the sufferer to imagine they have various other medical conditions. [6] | 
  | Hypothermia [7] | Illness caused by exposure to low temperatures. [7] |