List of minor diseases and medical conditions
This summary article lists minor diseases and medical conditions from the BattleTech universe, sorted alphabetically. Rather than referring to or severity or fatality, for the purpose of this list, a condition is considered "minor" if insufficient information about it is available in canonical sources to warrant its own article, and/or if it was only mentioned on the sidelines, rather than i. Finally, this list can be used as a stopgap to collect data on a disease or medical condition until enough information was published to warrant the creation of a fully-fledged article instead.
Named for the Taurian Concordat world of Brisbane, the Brisbane Virus is a degenerative nerve disease without a known cure. The most notable sufferer of the Brisbane Virus was Janice Calderon, the only daughter of Protector Thomas Calderon, who contracted the disease while visiting Brisbane during a grand tour of the Concordat in 3038. As of 3064, the New Avalon Institute of Science's College of Biology/Medicine was rumoured to have developed both a cure for the virus and a means of reversing the nerve damage it caused.   
A virulent and incurable form of viral encephalitis, Downing-Poltur's Disease is a neurological disorder that attacks the logic centers of the brain and provokes violent activity before brain swelling kills those infected. Downing-Poltur's Disease was considered extinct for centuries until its reappearance on Sabik in January 3078, the virus assumed to be released by Word of Blake insurgents after the loss of the world during Operation SCOUR.
A rare and fatal genetic disorder, the most notable victim of the disease was ComStar founder Jerome Blake. In Blake's case the early symptoms of the disease were attributed to injuries he had suffered during Operation CHIEFTAIN and it was not correctly diagnosed until it was too late.
Unspecified Nykvarn Virus
A viral plague with no given name native to the northern continent of the world of Nykvarn, this disease recurs annually and is treated by the consumption of loaves of bread made from a particular local grain. This disease would highlight Clan Smoke Jaguar ignorance and mismanagement after their conquest of the planet, when the Clan-installed governor shut down the only farm that produced the vital curative grain and ignored the warnings of the populace regarding the plague. A quarter of the the continent's population would perish from the plague that year, along with many Smoke Jaguars, including the governor, before the Scientist Caste could develop a vaccine. 
- The Periphery, 2nd Edition (sourcebook), pp.13, 14
- The Periphery, 2nd Edition (sourcebook), p.27
- Field Manual: Periphery, p. 27
- Handbook: Major Periphery States, p.47
- Jihad Hot Spots: Terra, p. 64, "Pandemic On Sabik"
- ComStar, p. 18 "A New Order - The Death of Blake"
- Invading Clans, p. 65 "Clan Smoke Jaguar - Occupation Zone (As of June 3052) - Second Wave - Nykvarm (DC)"