Retrograde Ejaculation: This condition occurs when semen enters the bladder instead of exiting through the penis during ejaculation, often resulting in a sudden change to watery or absent ejaculate. It can be caused by various factors, including diabetes, certain medications, or after surgeries like prostate or bladder operations.

Prostatitis: Inflammation of the prostate gland can lead to changes in semen consistency, including making it more watery. Other symptoms might include pain, difficulty urinating, and fever.
Semen Leakage: This can occur due to a variety of reasons including prostatitis, urethritis, or after certain medical procedures, leading to a sensation of watery semen.
Hormonal Imbalance: Hormonal changes, particularly those affecting testosterone levels, can impact semen quality and consistency.

Testicular Cancer: Although rare, testicular cancer can cause changes in semen, including its consistency. It's crucial to rule out this potentially life-threatening condition.
Spinal Cord Injury: Trauma to the spinal cord can affect the nerves controlling ejaculation, leading to retrograde ejaculation or changes in semen consistency.
Neurological Disorders: Conditions like multiple sclerosis, Parkinson's disease, or diabetes neuropathy can affect the autonomic nervous system, potentially altering ejaculation and semen characteristics.

Epididymitis: Inflammation of the epididymis, a tube at the back of the testicle that stores and carries sperm, can lead to changes in semen, though it's less commonly associated with watery semen.
Sjögren's Syndrome: This autoimmune disorder can affect exocrine glands, including those involved in semen production, potentially altering its consistency.
Young's Syndrome: A condition characterized by obstructive azoospermia (blockage preventing sperm from mixing with semen), chronic sinopulmonary infections, and bronchiectasis, which might result in changes to semen appearance due to the absence of sperm.