Definition [edit]. Hypoxemia refers to low oxygen in the blood, and the more general term hypoxia is an abnormally low oxygen content in any tissue or organ, or the body as a whole.Hypoxemia can cause hypoxia (hypoxemic hypoxia), but hypoxia can also occur via other mechanisms, such as anemia.ypoxemia (or hypoxaemia in British English) is an abnormally low level of oxygen in the blood.
At first glance, the most obvious difference between bilateral and unilateral contracts is the number of people or parties promising an action. Bilateral contracts need at least two, while unilateral contracts only obligate action on one part. The other differences might be a bit more subtle.
A real estate sales contract is a bilateral (two-way) agreement. The seller agrees to sell, and the buyer agrees to buy. Compare this with an option; an option is a unilateral (one-way) agreement in that the seller is obligated to sell, but the buyer is not obligated to buy--it is his option to do so.