Yawning problem. But all show normal.

Hello, Yawning excessively is when the act of yawning occurs repeatedly or in close succession. When you yawn, your mouth opens and you take in a deep, long breath. Sometimes this is accompanied by a sigh. Yawning is a normal response by the body to drowsiness or fatigue. Yawning may also be triggered by observing someone else yawning. Yawning excessively may mean taking in this deep breath more often, generally more than a few times per minute. This can occur when you are tired, weary or drowsy. Some medications, such as those used to treat depression, anxiety or allergies, can cause excessive yawning. Yawning excessively may indicate a sleep disorder, such as sleep apnea, that results in a lack of restorative sleep. Yawning excessively may also be your body’s reaction to a change in daily habits or work hours, such as taking on a night-shift job or working longer hours. Yawning excessively may also occur in the presence of a heart defect or disease. The vagus nerve acting on blood vessels can stimulate excessive yawning. This is called a vasovagal reaction and may be an indicator that you have a heart problem. If you have hypothyroidism or electrolyte imbalances, you may also feel drowsy during waking hours, which could also trigger excessive yawning. Seek prompt medical care if you are experiencing excessive yawning, or troubling you much. Consult consultant physician or neurologist.