Hello Consistency and volume of semen depends upon number of factors like How frequently you ejaculate? Nutritional status secretions of prostate and seminal vesicles Hygiene there are medicines available for erectile dysfunction, you need not to worry you can ask your doctor for sildenafil group of drugs In my opinion you need not to worry,this is not a serious problem If it gets even thinner or lumpy than it could be urethral discharge You should consult your doctor for seven analysis or urine culture to rule out the possibility of UTI Have plenty of fluids maintain good hygiene Multivitamin and food supplements to boost your heath and vitality Hope you will find my response informative and helpful please feel free to ask for follow up questions, I will gladly answer you Best wishes