Have you ever considered the fact that you were ill because there was too much blood in your body? How about curing yourself by drilling a hole in your skull to let evil spirits out? These questions may sound far-fetched to you, but there are those who believed--and, though far fewer—who still believe in these causes and treatments for certain health conditions.

Medicine has come a long way over the years, but some things have not changed. Here are nine strange but true medical practices that will leave you shocked, especially when you learn that many of them are still in use today.

1. Bloodletting.

This was a particularly common practice in ancient times all the way up until the late 19th century. The process involves the removal of rather large amounts of blood due to the belief that this will cure or prevent the patient from a variety of illnesses.

Bloodletting has not been proven efficient and, in modern times, has been discarded in all but a few specific conditions. The logic of bloodletting was based on the theory of the four humours. This theory described a mystical equilibrium between several bodily fluids which maintain human life, and would be disturbed by too much blood—resulting in illness. Today, the term for drawing blood for laboratory analysis or blood transfusion is "phlebotomy."

2. Hirudotherapy.

This technique, which utilizes leeches, was approved by the Food and Drug Administration (FDA) in 2004. Along with maggots, leeches were some of the first live animals to earn the FDA's approval.

For healthy people, the idea of coming near these creatures seems pretty grotesque, but for patients who are ill, the results are well worth it. Leeches have been capable of restoring healthy tissue when more high-tech medicine could not.

Medicinal leeches have been used for bloodletting—thought to be beneficial for whatever ailed patients—from Hippocrates' time through the mid-19th century. Currently, leeches are applied to the necessary site, from which they suck the excess blood and reduce the swelling in the tissues, promoting healing by allowing fresh, oxygenated blood to reach the area. The leeches also secrete an anticoagulant (known as hirudin) that prevents the clotting of the blood.

The leech's saliva is thought to be beneficial as well, providing a local anesthetic that the leech uses to avoid detection by the host. The leech's gut also holds a bacterium known as Aeromonan hydrophila, which helps in the digestion of ingested blood and produces an antibiotic that kills other potentially dangerous bacteria.

3.Maggot debridement therapy (MDT).

Maggots have shown to be quite efficient in the art of healing wounds. This was first visible centuries ago when wounded soldiers whose injuries were maggot-infested healed better than those whose were not. These maggots actually consume the dead tissue and leave the healthy, living tissues alone. Maggots also expel matter which restrains or even kills bacteria, proving especially useful in areas with poor circulation where antibiotics would be of little benefit.

Since the 16th century up until the 1940s, when antibiotic therapy and surgical techniques replaced it, the use of maggots was used and recognized for its healing abilities. In 1989, the advantage of MDT in certain cases over antibiotics was realized when maggots were proven to be more competent cleaners of wounds than any other non-surgical treatment. In 2004, maggots were approved by the FDA.

4. Fire cupping.

This technique is exactly what it sounds like. A vacuum is created by air heated by fire that's put in a glass cup and placed against a patient's skin. The cups are bell shaped and hold about 4 fluid ounces. Usually, 8 to 12 cups are placed on the patient's back in two parallel columns.

Circular marks are left on the patient's back—the darkness varies directly with how long the cups are left on. Usually, an application of about 20 minutes is average, for the back; however this can vary.

So, what is it for exactly? According to the American Cancer Society, this practice of Chinese medicine is "recommended mainly for treating bronchial congestion, arthritis, and pain. It is also promoted to ease depression and reduce swelling." Yet, the society states, "Available scientific evidence does not support claims that cupping has any health benefits."

5. Trepanation.

This surgery is performed by drilling or scraping a hole into the skull, in order to treat health problems related to intracranial diseases or for mystical purposes. Evidence of this practice has been traced all the way back to Neolithic times onwards. During prehistoric times, trepanation was thought to cure diseases by allowing the evil spirits and demons to escape through the hole that was created in the skull. Trepanation advocates and patrons still exist, believing this is the means to better health and longevity.

In modern times, the medical procedure of corneal transplant surgery also uses something known as trepanning or trephining. However, this is performed on the eye with an instrument called a trephine.

6. Laughter therapy.

We've all heard the expression, "Laughter is the best medicine," but is there really any truth in it? Many people believe there is. The practice of laughter therapy, also called humor therapy, is the idea of using humor to promote overall health and wellness. For years, the use of humor has been used in medicine (as early as the 13th century, surgeons used humor to distract patients from pain), and emerging research is showing that laughter may actually have therapeutic value.

In his 1979 book, Anatomy of an Illness, a man named Norman Cousins claimed to have cured himself of a serious illness with a regimen of laughter and vitamins after years of pain. This brought more attention to the idea of laughter as a source of treatment. Medical journals have recognized that laughter therapy can help improve quality of life for patients with unremitting illnesses. In addition, many hospitals provide laughter therapy programs as a complementary treatment to illness.

7. Malaria therapy.

No, this isn't therapy used to treat malaria. Instead, this was the idea of using malaria as therapy—more specifically, as a treatment for syphilis. Until the early 1900s, there was no treatment for the sexually transmitted disease (STD) when Viennese neurologist Wagner-Jauregg had the idea to treat syphilis patients with malaria-infected blood. The patients would then develop malaria, which would cause an extremely high fever that would destroy the syphilis bacteria. When that happened, they would be treated with the malaria drug quinine and cured of both ailments.

Of course, there were the side effects--such as the high fever, but they were worth the outcome, especially without any other options. Wagner-Jauregg even won the Nobel Prize for malaria inoculation in 1927, and the treatment was common until the development of penicillin came along and doctors had a safer and more efficient cure for the STD.

8. Seizure therapy.

Hungarian pathologist Ladislas von Meduna, who had the idea that seizures could be used to treat schizophrenia, engineered the idea of seizure therapy. Eventually, he found that camphor dissolved in oil worked in both animals and in humans.

On January 23, 1934, he tried the injection of camphor oil in a 33-year-old severely catatonic patient. After five treatments, catatonia and psychotic symptoms were gone. Meduna continued this treatment on more patients, and out of 26 patients, he achieved recovery in 10 of them and improvement in three.

Eventually, the side effects were too dangerous, including memory loss and broken bones, and seizure therapy was discontinued.

9. Insulin coma therapy.

In 1927, Viennese physician Manfred Sakel accidentally gave one of his diabetic patients an insulin overdose, which sent her into a coma. Upon waking, the woman, who happened to be a drug addict, claimed that her morphine craving was suddenly gone. When this mistake occurred again, with the same curative result, Sakel developed an idea.

Soon, he began intentionally testing what became known as insulin coma therapy on drug addicts and patients who suffered from schizophrenia and psychosis. He reported a 90 percent recovery rate, particularly among the schizophrenics. Some experts believe that the hefty dose of insulin causes blood sugar levels to plummet, which starves the brain of food and sends the patient into a coma. But why this would enable recovery for drug addicts or psychiatric patients is still not clear. Mathematician and inspiration for the film A Beautiful Mind, John Nash was actually a recipient of insulin coma therapy as a treatment for his schizophrenia.

Either way, the therapy was deemed dangerous—causing death in one to two percent of patients--and eventually eradicated.