Why is it that when the annual physical examination is normal, cancer is suddenly diagnosed?

It is generally believed that regular annual physical examinations can effectively prevent and detect various diseases, especially cancer, which is feared. However, in reality, there is a confusing and worrying situation: some people are suddenly diagnosed with cancer even though their annual physical examination results are normal. Why is this?

In fact, the focus of physical examination items for different age groups is:
20-30 years old:
People in this age group are generally in better health, but basic examinations cannot be ignored.
Pay attention to infectious diseases, such as conducting five tests for hepatitis B and chest X-ray to screen for hepatitis B and tuberculosis.
Pay attention to the health of the reproductive system. Women should undergo gynecological examinations and routine leucorrhea examinations, and men should undergo testicular examinations.
Do a basic physical examination, including height, weight, blood pressure, blood routine, urine routine, liver function, kidney function, blood lipids, blood sugar, etc.
30~40 years old:
Start paying attention to the thyroid gland and perform thyroid function and ultrasound examinations.
Increase intraocular pressure and fundus examination to prevent eye diseases such as glaucoma.
Women should focus on breast and gynecological tumors, such as breast mammography and gynecological ultrasound.
Married women should also take cervical smear and human papillomavirus (HPV) tests to screen for cervical cancer.
40-50 years old:
The risk of cardiovascular disease increases, so you need to pay attention to your heart health. You can do electrocardiogram, cardiac ultrasound and other examinations.
Emphasis on tumor screening, such as adding tumor marker testing (CA125, CA153, etc.), lung cancer screening, etc.
Men can add prostate-specific antigen (PSA) testing to screen for prostate cancer.
50-60 years old:
The risk of osteoporosis increases, and bone density testing is recommended.
The risk of gastrointestinal tumors increases, and regular gastrointestinal endoscopy is recommended.
Over 60 years old:
Comprehensive screening of various chronic diseases and tumors. In addition to the above items, carotid artery ultrasound, head CT, etc. can also be added according to physical conditions.
Strengthen the inspection of eye and ear diseases.

The occurrence and development of cancer is a complex and gradual process. In the early stages of cancer, the tumor may be very small or may not yet produce abnormal indicators that can be detected by existing detection methods. For example, some early gastrointestinal tumors may not cause obvious changes in the gastrointestinal mucosa, and routine blood tests and gastrointestinal endoscopic examinations may not be detected.

Some cancers may not have obvious symptoms in the early stages, or the symptoms may be very mild and easily ignored. For example, early pancreatic cancer may only cause occasional upper abdominal pain and indigestion, which can easily be mistaken for common gastrointestinal problems.

Normal annual physical examination results do not mean that you can rest easy. For the prevention and early detection of cancer, we need to remain vigilant, learn more health knowledge, and take more scientific and comprehensive preventive measures.