The lack of flow out after ejaculation may be a normal phenomenon, or it may be caused by pathological factors, such as low volume of sperm or semen, sperm non-liquefaction, ejaculation dysfunction and so on. 1. Normal phenomenon: the semen just ejaculated by men is a bit thicker and will not flow out of the body immediately after entering the female body. Usually about half an hour after ejaculation, the sperm starts to liquefy and can flow out of the body normally. 2. Low sperm or semen volume: If the sperm or semen volume is low, resulting in no flow out after ejaculation, it may be caused by disease factors, such as low sperm produced by the testes, blockage of the vas deferens, low androgen secreted by the testes, hypoplasia of the seminal vesicles, incomplete reverse ejaculation as well as dysfunctions in the prostate, urethral bulbourethral glands, seminal vesicle glands, and so on. 3. Sperm non-liquefaction: If the sperm is not liquefied, it may be caused by male prostatitis, endocrine disorders, etc. It may also be related to the female vaginal environment, such as the temperature of the vagina, vaginal pH and the composition of various enzymes in the vagina, which will lead to the ejaculate not flowing out. 4. Ejaculatory dysfunction: If ejaculatory dysfunction occurs, leading to retrograde ejaculation, there will also be no flow out after ejaculation. If the situation of not flowing out after ejaculation occurs frequently, it is recommended to go to the regular hospital as soon as possible for consultation and examination, so as to discover the problem in time and treat it in time.