Dr. Richard Zhang Cheng MD

Pertussis is an infection of the upper respiratory system. The disease is highly contagious and spreads through the coughing and sneezing of an infected individual. This highly contagious and airborne disease is caused by the bacteria called Bordetella pertussis. The symptoms of pertussis typically...

Hypothyroidism is a type of hormonal imbalance in which the thyroid hormones are in lower than normal. Essentially, it is the result of an underactive thyroid, and may be referred to as such. The two major hormones produced by the thyroid gland (T3 and T4) play an important role in your metabolism...

Hemorrhoids are caused when the veins in the rectum just above the anus get blocked due to external pressure. This causes obstructions in the blood flow and also leads to swelling of the veins. Hemorrhoids are classified as internal hemorrhoids, which are within the anal canal, and external...

IntroductionThe only way to prevent serious and life-threatening diseases such as meningitis is through vaccination. Meningitis can also be caused by viral, bacterial, and fungal infections. The infection usually affects the meninges or membranes that enclose the brain and spinal cord. Although...

Testicular cancer, affecting the testosterone and sperm-producing sex glands, the testicles, distresses not more than 1 percent of all men who are diagnosed with different types of cancer. But cancer of the testes is increasingly common between the ages of 15 to 34, particularly in the white...

Open gallbladder removal, also known as open cholecystectomy, is a surgical operation removing the gallbladder. The objective of the procedure is to offer permanent relief from gallbladder-related problems such as gallstones. During the surgery, a large incision is made in the abdomen and used to...