Objective is the medical term meaning without emotion.
extreme lack of attention to medical care
Wernicke's encephalopathy is the medical term meaning degenerative brain disorder caused by lack of thiamine.
Acapnia is the medical term meaning lack of carbon dioxide
elimination
atrophy
extreme hunger, lack of food, famine, undernourishment, malnourishment, fasting; deprivation of food; death from lack of food.
Clubbing is the medical term for the changes in fingernails or toenails associated with chronic lack of oxygen.
Anesthesiologist
Lack of expression or emotion.
Somnolent is the medical term meaning really sleepy.A related topic: Narcolepsy - It's a chronic sleep disorder, or dyssomnia, characterized by excessive daytime sleepiness (EDS) in which a person experiences extreme fatigue and possibly falls asleep at inappropriate times, such as while at work or at school.Somnolence
Agenesis is the medical term meaning absent development of an organ or tissue. Atresia is the medical term meaning congenital absence or development of a tube.
If you are referring to lack of or poor muscle tone then "hypotonia" is the correct medical term for low tone, and "atony" for absent tone.