A TBI can present several symptoms. The initial or apparent symptoms following an accident may include unconsciousness, dizziness, vertigo, nausea, headache or vision changes. Other symptoms may be less obvious. These can include difficulty concentrating, problems remembering new information, confusion, mood or personality changes, sleeping more or less than usual, irritability, nervousness, unusual anxiety, sensitivity to light or noise, feelings of sadness, emotional displays, difficulty choosing words, or difficulty performing daily tasks. Family and close friends are often the best people to detect TBI symptoms.