The first urine in the morning is very yellow and reddish, which may be caused by the concentration of urine, urinary tract infection, urinary stones and other reasons. 1. Concentration of urine: if the previous day too little water, sweating too much, etc. may lead to the concentration of urine, the phenomenon of urine is very yellow and red. 2. urinary tract infection: if the urinary tract infection, can cause the expansion of the capillaries under the mucous membrane, can appear in the morning the first urine is yellowish red phenomenon. 3. urinary stones: stone movement can cause mucosal damage, the first morning urine is very yellow and red phenomenon. In addition, there are many other reasons that can lead to the first morning urine is yellowish red, should go to the hospital in time to clarify the cause, if you need to treat, should be under the guidance of the doctor for standardized treatment, so as not to delay the condition.