By using buffer systems
Can be due to disease or medication.Are normal when breastfeeding. Can result in irregular periods in women, or breast discharge.
Blood sugar (or what is more specifically known as blood glucose level).
Eating foods that are low in cholesterol and participating in an exercise routine are the best ways to lower cholesterol. If that doesn't work, there are meds your doctor can give you to control it.
Then there is a chance that you have a tumor in your pituitary gland. You need further testing...