Stress is probably the largest threat to your glider's health.  If your glider is stressed for any reason, for any length of time, it can lead to a number of health issues.  When a glider is stressed, toxic bacteria will build up in its intestines.  Left untreated, the toxins can ultimately result in the death of your glider. 

Keeping a glider stress-free may not be 100% possible all the time, but there are things you can do to help alleviate stress and toxic build-up from becoming a problem in your glider.

Antioxidants like Vitamin E might be cytoprotective to the intestine or somehow maintain intestinal bacterial population stability. Adding a couple of drops of apple cider vinegar to the drinking water will help acidify the glider's digestive tract, making it less inviting to these types of bacteria. You can also give them occasional doses of Bene-Bac, which contains "good" bacteria cultures that help to combat the overgrowth of opportunistic "bad" organisms.

Companionship is important to community dwellers such as sugar gliders.  But human companionship will only go so far.  Gliders need the companionship of other gliders, too.  If all your glider has is the companionship of you, his or her owner, then the potential for your glider to becomed stressed whenever you are not around is a very real possibility, especially in times when you are unexpectedly away from your glider for a period of time.  If you have to go out of town for any reason, or become hospitalized, your sugarglider is left without your companionship and will become stressed.  Having at least two sugar gliders, so they can keep each other company, is the best preventative measure you can take to ensure your gliders do not become stressed due to lack of companionship.

Moving to a new home is another common cause of stress in a glider.  It is best to have a cage your glider considers "home" and have your glider's cage moved with him to the new place of residence. If you have to replace your glider's cage with a new/different one, do it in gradual stages by introducing him to his new environment a little at a time.

Sugar gliders may become paralyzsed in the hind end, causing them to drag their back legs. This may to be related to calcium deficiency, which will cause loss of bone mass and broken bones (particularly the hips). It can also happen in times of stress.

If you are breeding sugargliders, you need to take care that the mother does not become overweight.  Oftentimes, overweight mothers produce offspring that have white eyes, or white spots "floating" in their eyes. The ones with white eyes may be completely blind as the white will be fat buildup brought on by too much fat in the mother's diet.

Babies born with "white" (no black tip) tails seem to develop cataracts when they get older. By feeding the parents diluted (half water) carrot juice every day until the baby is weaned may help prevent the cataracts from developing.   Continue to give the babies carrot juice until at least a month after weaning.