When someone gets sick or begins to develop a long-term condition, identifying symptoms early is often the key to getting treatment that may cure or slow down the progression. Unfortunately, this quick diagnosis is not always possible.

Whether it is because the signs are too subtle or the symptoms indicate something else, some health issues do not get diagnosed until they have progressed.


Glaucoma is a group of eye diseases where the nerve in the back of the eye gets damaged, eventually causing vision loss and even blindness. In early glaucoma, symptoms may not be straightforward enough to indicate what the problem is.

Structural changes or vision changes can be the first sign, but neither one consistently appears before the other, making it difficult to connect the dots. When the disease advanced even a little, the changes in the eye and the person's vision are easy to identify.

Shot of a young woman getting her eye’s examined with a slit lamp PeopleImages/ Getty Images



According to the World Health Organization, about 1.28 billion people around the world have hypertension, and about 46% of them do not know they have it. Hypertension is treatable, but because there are no major symptoms, it is often only identified only when patients are actively screened for it.

People who go to regular checkups with their doctor get blood pressure screenings at every visit, but not everyone takes this consistent step. Experts theorize that public blood pressure screenings could increase early detection.

Hypertension In Older Age. Young Female Medical Worker Measuring Arterial Blood Pressure Of Senior Black Man Using Cuff, Patient Having Problems With Tension, Sitting At Table. Health Care Concept Prostock-Studio/ Getty Images


Deep Vein Thrombosis

Serious complications can arise from deep vein thrombosis (DVT), which occurs when blood clots develop in one of the large veins, most commonly in the leg or calf. In some patients, DVT causes tenderness, swelling, pain, redness, and discoloration, but about half of the people with DVT have few or no symptoms.

The most severe complication of DVT is pulmonary embolism (PE). PE occurs when a clot breaks loose and travels through the heart and into the lungs. It is a serious, life-threatening condition, and this makes identifying a DVT as early as possible that much more important.

Woman siting on couch and holding shin with her hand closeup. Prevention of varicose veins concept megaflopp/ Getty Images



Physicians often suspect dementia when someone's primary caregiver raises a concern, but https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2787842/" title="Alzheimer's Disease and Associated Disorders" desc="Missed and Delayed Diagnosis of Dementia in Primary Care: Prevalence and Contributing Factors">early symptoms of dementia may not be apparent and may be confused with typical signs of aging. Primary care doctors may miss the severity of symptoms due to how briefly they spend time with the patient and because many older patients have other health conditions that need to be addressed.

Home caregiver helping a senior woman standing in the bedroom FG Trade/ Getty Images


Hepatitis C

Hepatitis C is a liver disease caused by a virus. Some people with hepatitis C have a very mild illness; others get really sick and require hospitalization. Many people who have it do not have any symptoms or realize they are infected.

People can live for years with hepatitis C and not experience any symptoms; when symptoms do appear, they are often due to advanced liver damage. The only way to know if you have hepatitis C is to get tested.

Portrait of upset black woman suffering from strong abdominal pain in right side, touching her tummy, sitting in bed at home. Sad afro lady feeling acute stomachache, free copy space Prostock-Studio/ Getty Images



Osteoporosis is pretty prevalent. Over 50 percent of postmenopausal women will have a fracture related to osteoporosis, and of them, only about a third will be able to return to independent living.

Yet osteoporosis rarely has any symptoms. Many people do not even realize they have it until they fall and break a bone.

Doctor checking a senior female patient's x-ray image during a visit at the hospital, injury and osteoporosis concept demaerre/ Getty Images



In the United States, chlamydia is the most commonly reported bacterial infection and is responsible for most sexually transmitted infections worldwide. The bacterium that causes this infection can affect the cervix, urethra, and prostate.

Despite this, about 70 percent of women with chlamydia are asymptomatic or have common and fairly mild symptoms like abdominal pain, vaginal discharge, and bleeding. The classic presentation for women with chlamydia is mucusy discharge and cervical bleeding, but fewer than half with the infection have these symptoms.

couple having an appointment in a clinic, close up of their bodies


Obstructive Sleep Apnea

People with obstructive sleep apnea may experience excessive sleepiness, but unless they sleep with a partner who tells them, they might not realize the condition is a possibility for them. Although obstructive sleep apnea is common, https://pubmed.ncbi.nlm.nih.gov/32286648/" title="JAMA" desc="Diagnosis and Management of Obstructive Sleep Apnea: A Review">many people are asymptomatic, which may lead to the diagnosis being missed. People with obstructive sleep apnea are two to three times more likely to experience metabolic or cardiovascular disease, making an accurate diagnosis essential.

Happy and healthy senior woman sleeping deeply on her back with CPAP machine mask and hose. cherrybeans/ Getty Images


Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is pretty prevalent in the western world. It is an accumulation of fat in the liver and generally occurs in people with obesity.

Most people who have NAFLD do not have obvious symptoms. They may complain of daytime sleepiness or fatigue, which can appear in many conditions. Other symptoms, like cognitive impairment and falls, can also be attributed to other things, making it difficult for doctors to reach an accurate diagnosis.

Asian Female Doctor Wearing Face Mask Is Showing Liver Model


Colorectal Cancer

People with colon cancer do not usually have symptoms early on in the disease. https://www.ncbi.nlm.nih.gov/books/NBK470380/" title="Stat Pearls" desc="Colon Cancer">About 11 percent of cases are found during a routing asymptomatic screening. Logically, when cancer is diagnosed promptly, it is usually in an earlier stage, which is why the CDC suggests starting regular screenings at age 45.

close up of female doctor hand wear white coat holds blue ribbon in front of her chest with colon model on table PonyWang/ Getty Images


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