What causes nightmares?

The causes of nightmares are complex and varied, mainly including: 1. Psychological factors: Negative emotions such as emotional stress, mental tension, anxiety, and depression may manifest in dreams and potentially lead to nightmares. 2. Environmental factors: Poor sleep environments, such as noise, bright lights, cold or excessive heat, and improper sleeping positions, may also contribute to nightmares. 3. Lifestyle habits: Exposure to frightening or stimulating content before sleep, such as watching horror movies or listening to thrilling stories, can easily trigger nightmares. 4. Medical conditions: Certain physical illnesses, such as anemia, heart disease, hypoglycemia, and sleep disorders (such as nightmare disorder), may also lead to frequent nightmares. It is recommended to adjust lifestyle habits according to individual circumstances and seek professional medical advice when necessary.