Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
numbness, tingling, or burning pain in your hands or feet;
skin numbness or purple discoloration;
skin ulcers or open sores;
sudden chest pain, wheezing, dry cough, feeling short of breath;
low blood cell counts--fever, chills, tiredness, mouth sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed; or
signs of liver or pancreas problems--loss of appetite, upper stomach pain (that may spread to your back), nausea or vomiting, fast heart rate, dark urine, jaundice (yellowing of the skin or eyes).
Common side effects may include:
loss of appetite, nausea;
constipation, diarrhea;
low blood cell counts;
bleeding; or
mouth sores.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Hydrea side effects (more detail)
