Most toddlers sleep 10 to 13 hours a day, so it's possible your toddler is not getting enough sleep if he skips naps or wakes up frequently at night. Mononucleosis, hypothyroidism and anemia are possible causes of your child's consistent fatigue. Consult with your doctor if your toddler's symptoms seem excessive.
Flu-like symptoms are common with mononucleosis, as well as a sore throat and swollen lymph nodes of the neck, groin or armpits. A fever is present with mononucleosis, but the fever is low for toddlers. If hypothyroidism is causing the tiredness, your toddler may have increase sensitivity to cold temperatures, pale skin, muscle weakness, poor mental development, muscle aches and weight gain. Your toddler's face also may appear puffy. Anemia also causes fatigue and pale skin, but you toddler may be irritable and dizzy and have a rapid heart beat, as well.
Mononucleosis is a viral infection caused by the Epstein-Barr virus. It's known as the kissing disease because it's passed person to person by saliva. Your toddler can catch this virus drinking from an infected person's cup, putting a contaminated toy in his mouth or getting a kiss on the lips from an infected person. Hypothyroidism is caused by the thyroid gland not producing enough thyroxine and triiodothyronine hormones. These hormones help maintain homeostasis in the body with regard to carbohydrate and fat distribution, body temperature, heart rate and protein production. Autoimmune disorders, which cause antibodies to attack your own tissues, are one cause of hypothyroidism; others include radiation therapy for hyperthyroidism and cancer treatments, pituitary gland malfunction and the partial or full removal of the butterfly-shaped thyroid. About 1 in 3,000 infants is born with a defective thyroid gland or no thyroid gland, according to MayoClinic.com. Anemia is caused by the red blood cell count being too low from blood loss, bone marrow malfunction and iron deficiency.
Since mononucleosis is viral, there are no antibiotics to make your child feel better. Rest, increased fluids and over-the-counter acetaminophen or ibuprofen can help relieve symptoms. If the tonsils swell, making breathing difficult for your toddler with mononucleosis, seek emergency medical attention. Hypothyroidism usually is treated with a synthetic thyroid hormone called levothyroxine, which is taken daily and reduces your toddler's fatigue within two weeks. This often is a lifelong treatment. If your child has iron deficiency anemia, doctors will prescribe medication so your toddler's body can build the amount of stored iron. Add foods rich or fortified in iron to your toddler's diet. If anemia is severe, your toddler may need a bone marrow transplant or blood transfusion or his spleen removed.
Frequent hand-washing is the best way to prevent the spread of infectious viruses, such as the Epstein-Barr virus. Do not allow your toddler to share eating utensils with anyone and try restricting the number of people who kiss your child. If your toddler has mono, keep him home from day care. To prevent iron deficiency anemia, your child should not drink more than 24 to 32 oz. of milk each day, according to KidsHealth. Too much milk can quickly make your toddler feel full, so he loses interest in eating foods rich in iron. There is no way to prevent hypothyroidism or anemia from genetic defects.