The disease screening experts recommend at every age to catch cancer early like Princess Kate

England's Princess of Wales, Kate Middleton, sadly announced her cancer diagnosis last week. 

Though her stage of disease has not been officially confirmed, it appears as though the cancer was spotted in early stages since she's undergoing 'preventative chemotherapy'. 

If tumors have advanced to other areas of the body, more aggressive types of chemotherapy are traditionally given to kill remaining cancer cells. 

Kate Middleton also said in her public address that she's feeling 'well' and has assured her three young children she is 'going to be ok'.

You shouldn't wait until you're elderly to begin screening for diseases, doctors say

The young royal's case highlights how important regular screening for diseases can be.

And not just for cancer - doctors recommend a number of preventative tests for every stage in life to stave off your risk of heart disease, diabetes and other conditions.

Regular screenings at an early enough age could have a huge impact on the outcomes of all diseases, Dr Robert Biernbaum the chief medical Officer for Wellnow Urgent Care, told CBS News HealthWatch . 

'Instead of seeing end stage breast cancer, end stage colon cancer, we would catch them at a younger age and they would have a better outcome. So prevention is the key to being healthy,' he said. 

Here are the essential tests you should take at every stage of life.

In your 20s, get an early wrangle on your sexual health

Doctors recommend starting regular STI testing as soon as you become sexually active

The Princess of Wales is said to have waited until her three young children were on Easter break before she broke the news of her diagnosis to the nation. 

In your twenties you should be focusing on screenings that will help you know your risks for developing diseases later in life, Dr Nadia Javaid, a family practitioner, told State Health Benefit Plan. 

This includes taking regular sexually transmitted infection tests, diabetes screeners and cholesterol tests. 

At this point in your life, there are still many lifestyle adjustments you can make that will help stave off future disease, Javaid said. If you know you're at higher risk, you have a better chance at taking action.  

For example, say you take an STI test and discover that you have human papilloma virus. There are immediate surgical steps you can take that will help prevent developing cancer from developing later in life, according to the WHO. 

Diabetes screening should also start happening at this age because of the uptick of obesity in America, Biernbaum said. 

Prince William, Princess Kate, pictured with Prince George, Prince Charlotte and a baby Prince George at Anmer Hall in December 2018

If you know you're at higher risk for developing diabetes when you're twenty, you can start practicing new habits, like consuming less sugar and exercising more regularly, to decrease the chance that you develop the disease. 

You should also continue screening habits that you might have already developed - by visiting a dentist, dermatologist and eye doctor. Specifically, you should be seeing a dentist twice a year for an examination of your teeth and gums, according to the American Dental Association. 

Finally, Biernbaum recommends checking in with a mental health professional at this age, especially if you haven't already. 'In reality that screening should be started at age 12 and it should be continued every single year during a person's life,' he said. 

From this age on, STI, mental health, oral, skin and eye care exams continue to be recommended by physicians throughout life. according to CBS News. 

In your 30s, keep an eye out for funny moles

Checking moles can help prevent skin cancer

In your thirties, the American Heart Association recommends beginning to look out for your heart health. To do so, you should get your blood pressure checked every two years, and  your cholesterol check every four years. 

Also, at this point in your life, you've probably been exposed to enough sun to have potentially developed some funny-looking moles - which could be cancerous. The Skin Cancer Foundation recommends getting a yearly dermatological exam to make sure freckles are just freckles. 

If you've been lucky enough not to require glasses or contacts up to this point, you might never have darkened the doorstep of an optometrist. 

But the American Academy of Ophthalmology recommends getting examined at least twice in your thirties, in order to make sure there aren't problems hiding behind your eyes.

Doctors also recommend being vigilant with your sexual health- making sure to  screen for cervical and testicular cancer. 'Unfortunately, we know there is a higher risk of testicular cancer in your 20s and 30s,' Dr Steven Lamm, from NYU Langone, told CBS News.  

In your 40s, prepare for colon screening 

Colorectal tests aren't as invasive as they used to be

The US Centers for Disease Control recommends you begin taking colorectal exams regularly starting at age 45. 

Luckily, not all of these screeners require you to undergo an uncomfortable colonoscopy, as there are now over the counter exams which work well, Biernbaum said. 

At age 40, doctors from the American College of Radiology also recommend that women get their first mammogram, if they haven't already had one. From there, the ACR recommends women get tested every other year to keep on top of potential breast cancer. 

Also, women should be talking to their doctor about the symptoms of menopause at their yearly visit starting around this age. Perimenopause, the beginning stage of 'the change', can last as long as ten years, and usually begins in your early 40's, Dr. Jessica Shepard told CBS News. 

At this stage, you should be sure to continue your monitoring of heart health and diabetes risk, as your cardiovascular system continues to age, the AHA recommends. 

In your 50s, look out for lung health

New recommendations state that people should start screening for lung cancer when they hit their 50s

Once you reach this decade, doctors recommend getting screened for lung cancer. This new guideline from the American Cancer Society states that if you were a habitual smoker, then you should repeat these exams annually. 

Starting at age 55, the US Preventative Services Task Force recommends that men begin considering a prostate exam. They should talk to their doctor about their likelihood of developing prostate cancer, and then decide how frequently they should be checked for the disease. 

The other gamut of tests are still recommended- from sexual health to dental check ups, and Dr Céline Gounder told CBS that taking these now could save your future health. Even at age 50. 

'If you're still a smoker, quit smoking. If you don't exercise at all, even just walking a little bit every day, taking the stairs instead of the elevator — very small things can really make a big difference for your health,' she said.  

In your 60s, be considerate of your bones 

Bone health and density decreases with age, especially in women

At this stage, most women will have gone through menopause, which can cause big changes in bone density. As such, the Office of Disease Prevention and Health Promotion recommends that women 65 and older take bone density tests. 

Though women are particularly at risk for conditions related to bone density- like osteoporosis, men might also want to look into similar tests at this age, the office says. Taking this sort of test, which usually just involves an X-Ray, can give you an idea if you're at higher risk for developing bone fracture. 

When men enter this decade, they might be at higher risk for blood clots, especially if they were smokers. So if you're a 65 year old male smoker, the USPSTF recommends exploring abdominal aortic aneurysm tests. 

These tests check that the large blood vessels that deliver blood to the body are unobstructed. 

Lung, colorectal, prostate and breast exams are important to continue through this age too, alongside the regular maintenance, like skin, mouth and eye exams.