Essentially, akathisia is a feeling of agitation in the body, under the skin. Most sufferers will say their muscles feel like they are quivering. The ‘motor restlessness' induces motion and moving makes the condition better. Sitting still or sleeping makes it worse.
One of the most common drug categories to induce akathisias are the “neuroleptics”, which are medications for psychosis, schizophrenia or other mental-health related conditions. This category of medications are known chemically as dopamine antagonists (they block dopamine receptors). Some people experience akathisias as a result of their antidepressant or nausea medicine; also during drug withdrawal from various medications including opioids, barbiturates, cocaine, benzodiazepine and alcohol.