Underlying Illnesses
There is a myriad of underlying illnesses that can cause insomnia. People suffering from respiratory illnesses like the cold or the flu may have difficulty sleeping due to nasal blockages. The inability to fully take in breath makes it difficult to sleep. Nasal problems can also cause headaches and fever, further preventing night rest.
Studies have shown that persons suffering from gastroesophageal reflux disease (GERD) [2] or Acid reflux often find it hard to rest at night. This condition causes a burning sensation in the chest, known as heartburn. This pain is worsened when you bend over or lie down, and this may prevent you from falling asleep on time.
Diabetic patients may also suffer [3] from insomnia due to fluctuations in blood sugar levels. Hypoglycemia (low blood sugar) at night may make it difficult to rest and can cause sleepiness during the day. Other conditions like thyroid and obstructive sleep apnea (OBS) have also been linked to insomnia.