How will inhaling nitrous oxide recreationally effect the body?

Possible death: The problem is not with the n20, but with the nitrous displacing the oxygen you need. When administered professionally, the nitrous is mixed with pure oxygen, allowing your body to maintain enough in your bloodstream to survive. Breathing in nitrous with just regular air causes the oxygen to be displaced, resulting in hypoxia. It's the law of partial pressures for gasses.

Nitrous oxide: Nitrous oxide is not safe for recreational use.

Dangerous: Recreational use of nitrous is dangerous because there is no way to monitor your oxygen level. You must breath 20% o2 or you may become hypoxic , and while under the nitrous oxide influence, death could result.

Very serious : Inhaling nitrous on regular basis might cause decreased oxygen body intake , and you have no control over the mixture while you under the mask , making it very dangerous for the body and might result in a collapse and eventually death.

Adversely: Nitrous oxide (n2o) is an anesthetic gas administered in the course of general anesthesia and for dental anesthesia . It is an odorless, colorless gas that is supplied in pressurized tanks. It was the first anesthetic gas discovered in the 1840s in the us. With repeated exposure n2o can cause bone marrow and nervous system damage associated with B12 deficiency. As such, it is no longer widely used.