If you feel sick during your dream it could mean the actual sickness you are suffering from. Perhaps you have the illness you havent known yet. Sometimes people are very afraid to get sick, therefore they dream about their fears. If you are sick in reality, it is simply a reflection of it. If you ae vomiting in the dream, please see the meaning of vomiting.
Sickness dream meaning
Read more about dreaming of Sickness in other dream meanings interpretations.