Dancers are typically very busy people. They usually have a job and kids just like a lot of other women, only they are also squeezing in dance classes, costume fittings, photo sessions and performances. That can make for a person that's pretty ragged around the edges at the end of the day.
Therefore, getting enough sleep and rest is critical to good health. Not to mention a good diet, vitamins and suppliments and times of relaxation. When we sleep our body is working to heal itself. And all too many dancers are on the road a lot and eat a lot of fast food. So listen to your body and see if it's telling you to rest, eat fresh foods, or slow down a little.
I know a lot of dancers smoke too. That's like shooting yourself in the foot. Your body is your instrument. Take care of it or you'll be sidelined.