This is perfectly normal. They find themselves constantly bent over, preoccupied with the location of the nearest bathroom and whether their most recent meal is going to stay down or not. The joy of their pregnancy turns into a nightmare of nausea. But in the meantime, months of severe nausea can strain a marriage and hinder job performance, leaving permanent scars. For many years, nausea and vomiting during pregnancy was considered to be primarily psychosomatic in nature, representing an unconscious rejection of the fetus and associated with low intelligence and frigidity.
More recent studies suggest that it is a physical condition caused by hormonal effects.
NVP is a physical illness, but the psychological effects can also present a challenge. Perhaps the hardest aspect of morning sickness is that not every pregnant woman suffers from it. People who have not experienced NVP themselves or with a loved one can be unsympathetic. My wife ran marathons when she was pregnant. Denial is common, as NVP doesn't fit into plans for a glowing, happy pregnancy.