Many conditions, lifestyle choices, medicines, and diseases interfere with your ability to heal or fight infection. You may be at risk for a more serious problem from your symptoms if you have any of the following. Be sure to tell your health professional.

Conditions

• Age younger than 3 months
• Age older than 60 years
• Breast-feeding
• Burns
• Conditions that cause increased fluid loss, such as:
  • Diarrhea
  • Fever
  • Vomiting
  • Stomach and bowel disorders that cause fluid to move through the body too quickly
• Eating disorders, such as anorexia or bulimia
• Mental retardation or another developmental delay
• Obesity
• Pregnancy
• Dialysis
• Inability to talk or communicate because of another condition, such as Alzheimer's disease or a stroke

Lifestyle choices

• Alcohol abuse or withdrawal
• Drug abuse or withdrawal
• Sports or other activities that increase sweating
• Smoking or other tobacco use

Medicines

• Antihistamines
• Blood pressure medicines
• Corticosteroids, such as prednisone
• Diuretics
• Laxatives
• Medicines to prevent organ transplant rejection
• Medicines used to treat cancer (chemotherapy)
• Psychiatric medicines
• Radiation therapy

Diseases

• Addison's disease
• Cancer
• Cystic fibrosis
• Diabetes
• Gallbladder disease
• Heart disease
• Human immunodeficiency virus (HIV) infection
• Hyperthyroidism
• Irritable bowel syndrome
• Kidney disease
• Liver disease, such as hepatitis
• Pancreatitis
• Stomach and bowel disorders, such as ulcers or gastritis