There appear to be three general categories for classifying the means through which CJD may be acquired.

1. The disease can occur sporadically Sporadic Creutzfeldt-Jakob Disease.
2. The disease can be inherited - Inherited Creutzfeldt-Jakob Disease
3. The disease can be transmitted through infection Creutzfeldt-Jakob Disease Through Infection.

There are several common symptoms evident in CJD patients as the disease runs its course. The duration of CJD from the onset of symptoms to the inevitable death is usually one year. However, shorter duration periods of several months are common, and longer duration periods of two or more years have been noted, usually in the familial form and with an earlier age of onset.
The initial stage of the disease can be subtle with ambiguous symptoms of insomnia, depression, confusion, personality and behavioural changes, strange physical sensations, and problems with memory, co-ordination and sight. As the disease advances, the patient experiences a rapidly, progressive dementia and in most cases, involuntary and irregular jerking movements known as myoclonus. Problems with language, sight, muscular weakness and co-ordination worsen. The patient may appear startled and become rigid. In the final stage of the disease, the patient loses all mental and physical functions. The patient may lapse into a coma and usually dies from an infection like pneumonia precipitated by the bedridden, unconscious state.