What's the reason for a 16-month-old baby clenching teeth while forcefully using both hands?

It is possible that a 16-month-old baby clenching their fists and grinding their teeth is a normal phenomenon, but it could also be caused by negative emotions, calcium deficiency, or other factors.

1. Normal phenomenon

At 16 months of age, a baby's muscular and nervous systems are not yet fully developed, which may lead to involuntary behaviors such as clenching fists, grinding teeth, or tensing the whole body. Generally, these symptoms will quickly disappear as the child grows older and the nervous system matures.

2. Negative emotions

When a baby is angry or frightened, they may express these negative emotions by tensing their hands, grinding their teeth, or straining their entire body. Symptoms typically ease after receiving adequate comfort and reassurance.

3. Calcium deficiency

Babies at 16 months grow rapidly and require higher amounts of calcium. Insufficient calcium intake can lead to deficiency. Calcium deficiency may increase cortical excitability in the brain, resulting in symptoms such as clenched fists, teeth grinding, and full-body straining. Additional signs may include night sweats,枕秃 (hair loss at the back of the head), and restless sleep. A medical evaluation for trace elements should be conducted, and calcium supplementation—such as calcium gluconate oral solution—should be taken according to doctor’s instructions. Increased sun exposure can also help enhance calcium absorption.

If the baby frequently exhibits fist clenching and teeth grinding, especially when accompanied by foaming at the mouth or whole-body tremors during episodes, epilepsy should be suspected. Prompt medical evaluation is necessary for accurate diagnosis and appropriate treatment.