Spins

The spins (as in having "the spins") is an adverse reaction of intoxication that causes a state of vertigo and nausea, causing one to feel as if "spinning out of control", especially when lying down. It is most commonly associated with drunkenness or mixing alcohol with other psychoactive drugs such as cannabis. This state is likely to cause vomiting, but having the spins is not life-threatening unless pulmonary aspiration occurs.

The most common general symptom of having the spins is described by its name: the feeling that one has the uncontrollable sense of spinning, although one is not in motion, which is one of the main reasons an intoxicated person may vomit. The person has this feeling due to impairments in vision and equilibrioception. Diplopia (double vision) or polyplopia are common, as well as the symptoms of motion sickness and vertigo.

Ingesting a great deal of alcohol in a short amount of time causes alcohol to quickly enter the bloodstream. Mixing alcohol with normal soft drinks, rather than diet drinks delays the dizzying effects of alcohol because the sugary mixture slows the emptying of the stomach, so that drunkenness occurs less rapidly.

The dizzying effects of alcohol upset the fragile mechanism that the inner ear uses to balance.

"Balance in the body is monitored principally by two systems, both of which are affected by alcohol sending abnormal impulses to the brain, [which tells it] that the body is rotating, causing disorientation and making the eyes spin round to compensate."

This "upset" has been seen in experiments in which human subjects were given clinical tests of the vestibular system before and after ingesting alcohol. The alcohol apparently causes the ampullary cupula in the semicircular canal to become lighter than the surrounding fluid (endolymph), which causes the system to become sensitive to gravity in addition to rotational acceleration.

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Wikipedia