Hypogonadism: This condition, characterized by low testosterone levels, can lead to decreased libido, erectile dysfunction, and changes in semen quality. The reduction in testosterone can also affect the intensity of orgasm, leading to less feeling when ejaculating.

Diabetes Mellitus: Diabetes can cause neuropathy, leading to decreased sensation and potentially less feeling during ejaculation. It can also contribute to erectile dysfunction due to vascular complications and neuropathy.
Depression and Anxiety: These mental health conditions can significantly affect sexual function, including libido and the ability to achieve or maintain an erection. They can also indirectly affect the sensation during ejaculation due to psychological factors.
Medication Side Effects: Certain medications, such as antidepressants, antihistamines, and blood pressure medications, can have sexual side effects including decreased libido, erectile dysfunction, and changes in ejaculation.

Prostate Cancer: Although less common, prostate cancer can cause changes in ejaculation and semen. It's crucial to rule out this condition, especially in older men or those with a family history of prostate cancer.
Neurological Disorders (e.g., Multiple Sclerosis, Parkinson's Disease): These conditions can affect sexual function by damaging the nerves that control erection and ejaculation, leading to the symptoms described.
Pituitary Tumors: Tumors in the pituitary gland can affect hormone production, including testosterone, leading to hypogonadism and its associated symptoms.

Klinefelter Syndrome: A genetic condition that affects male development, including reduced testosterone production, which can lead to the symptoms described. However, it is typically diagnosed at a younger age.
Ejaculatory Duct Obstruction: A blockage in the ejaculatory ducts can cause changes in semen and potentially affect the sensation of ejaculation. This condition is relatively rare and might require specific diagnostic tests to identify.
Retrograde Ejaculation: A condition where semen enters the bladder instead of exiting through the penis during ejaculation, which can be caused by diabetes, surgery, or certain medications. It can lead to a decrease in the sensation of ejaculation.