There are over hundreds of sexually transmitted diseases but the most common sexually transmitted diseases that exist are as follows:
Chlamydia
Chlamydia is the most common sexually transmitted disease caused by a bacterium, Chlamydia trachomatis. It mostly has no visible symptoms but some women do experience lower abdominal pain, low back pain, nausea, fever, pain during intercourse, or bleeding between menstrual period. The symptoms tend to appear within 1 to 3 weeks after exposure.
Men with signs or symptoms might have a discharge from their penis or a burning sensation when urinating. Other common symptoms in men are burning and itching around the opening of the penis, while in some rare cases there is pain and swelling in the testicles .
This bacterial can also infect the rectum if not treated early.
Gonorrhoea
Gonorrhoea can cause infertility in women and is caused by Neisseria gonorrhoeae, a bacterium that grows and multiplies quickly in moist, warm areas of the body – such as the cervix, urethra, mouth, or rectum.
Women suffering from gonorrhea, may experience bleeding after sex and frequent, painful urination. These symptoms are especially common in the early stages of an infection of the cervix. Later symptoms include nausea, fever, vomiting, bleeding between periods, and a yellow or bloody vaginal discharge.
Men experience pain while urinating, frequent urination, and swollen testicles. This indicates an infection of the urethra. There is also white, green, or yellow discharge from the tip of the penis.
Gonorrhoea of the rectum can occur in people who practice anal sex and also infects the throat of those practising oral sex. In pregnant women, gonorrhoea can be passed from an infected woman to her newborn infant during delivery.
Genital herpes
Genital herpes is a highly contagious viral condition caused by the herpes simplex virus (HSV). It infects the skin and mucous membranes of the genitals or rectum, but it can also appear in areas such as the mouth, particularly the lips.
Its chief symptom is an outbreak of small blisters, and these can be very painful. It's transmitted primarily through physical and sexual contact. During birth, the presence of herpes simplex virus in the birth canal is a threat to the infant's life.
Genital herpes cannot be cured. But there are medications that can be prescribed to treat outbreaks and minimize the symptom
HIV and AIDS
AIDS is a potentially lethal disease, which is caused by the HIV virus. HIV means 'human immuno deficiency virus'.
HIV invades and destroys the immune system, which protects the body from infection. This means that a person who carries the HIV virus is prone to many different illnesses and may die from diseases that are harmless to healthy people.
In some countries, particularly those located in Sub-Saharan Africa, the HIV rates are very high. For instance, in the Republic of South Africa it's estimated that about 11 per cent of the population is HIV-positive.
Genital warts
Gential Warts, or condylomata acuminata, are caused by the human papilloma virus (HPV). It takes a long time for the infection to surface in form of warts making it difficult to identify the source of the disease transfer.The HPV virus in some cases leads to development of cervical cancer in women
Syphilis
Syphilis is a dangerous and life-threatening disease and is required to be treated on priority. It's caused by a corkscrew-shaped germ called Treponema pallidum. This infection appears like a small lump and this soon breaks down to form a painless ulcer. The second stage is characterised by fever, rashes and throat ulcers and eventually the germs may attack the brain, spinal cord and other organs.
Trichomonas
Trichomonas vaginalis causes a green or yellowish, bubbly vaginal discharge and intense vulvae soreness in the vagina. It also produces a 'fishy' smell. However, some women have no symptoms at all, and men rarely do.
Bacterial vaginosis
BV is a common cause of vaginal discharge. The discharge is usually whitish or greyish or sometimes yellowish, and tends to have an off-putting ‘fishy’ odour. Unlike the discharges caused by thrush or trichomonas, it’s not usually associated with soreness, discomfort or itching.
Molluscum contagiosum
Molluscum contagiosum is a viral condition that causes little 'pearly bumps' on the skin that is flesh-coloured, dome-shaped papules. With time, the center becomes soft and indented (umbilicated) with a white curd like core. This core may be squeezed out easily. It is one the most contagious diseases and can be easily transmitted by direct contact, either person to person or by shared items, such as clothing, towels, and wash clothes.