What causes morning sickness?

Increased estrogen. It is felt to be caused by an increase in circulating estrogen during pregnancy. Morning sickness can actually occur at any time of the day. It usually resolves by week 12.
Thyroid . We are not entirely sure but there is some evidence to suggest it is because of transient overactivity of the thyroid. It probably is a primitive protective mechanism to prevent exposure to spoiled or rotten food.
Progesterone. Its from increasing levels of Progesterone mostly. Progesterone is known to relax smooth muscle in the stomach and esophagus, and cause nausea and heartburn. Just ask anyone who has taken the morning after pill.

Related Questions

What causes morning sickness? Any remedies for it?

Hormones. It is a reaction to pregnancy... Can be worse in some patients... Reccomend bland diet, vitamin b6, and unisom as needed...Also several rx meds that can help. Read more...
Ginger. A simple way to reduce nausea is with ginger. You can drink slightly flattened ginger ale or nibble on crystallized ginger. Or pour boiling water over freshly sliced organic ginger & steep x 5 min in a covered pot. Sip. Aromatherapy: sweet orange (citrus sinensis), peitigrain (citrus reticulata), mandarin (citrus reticulata) are different citrus scents that can decrease nausea. Read more...

What causes morning sickness when not pregnant?

If u are not preg. Then it cannot be morning sickness, nausea in the morning can be due to many causes, a virus, ulcer, other stomach or esophagus problems, liver , gall bladder or pancreas problems, etc. , please call your gp for a work-up. Read more...

What's the cause of morning sickness?

Hormone changes. Pregnancy hormones rapidly increase early in the pregnancy, which causes nausea and vomiting in many (but not all) women. Morning sickness is something of a misnomer as I have rarely seen the nausea confined to just the morning. Read more...

What other things can cause morning sickness besides pregnancy?

Causes for nausea. There are many possible reasons for nausea. Please see this extensive list of possible causes of nausea by mayo clinic: http://www.Mayoclinic.Com/health/nausea/my00572/dsection=causes. Read more...