Vitamin B₁ deficiency can lead to symptoms such as difficulty concentrating, depression, weight loss, and loss of appetite. Vitamin B₁ deficiency, also known as beriberi, is a systemic condition caused by inadequate intake of vitamin B₁. The disease mainly involves the nervous system, digestive system and circulatory system. The main symptoms include headache, fatigue, muscle pain, nausea and vomiting, lack of concentration, depression, loss of appetite, weight loss and so on. Oral supplementation of vitamin B₁ can be used for mild cases of the above symptoms, while injection of vitamin B₁ should be given immediately for severe cases with gastrointestinal disorders affecting absorption. Improving dietary habits and ensuring a balanced intake of nutrients can help prevent vitamin B₁ deficiency. Feeling unwell, it is recommended to go to the hospital in time, under the guidance of a professional physician for standardized treatment. The above medication should be used in accordance with the doctor’s instructions.