Thyroid cancer is one of the most commonly diagnosed cancers in the United States, with roughly 45,000 new cases expected in 2026 and over a million Americans currently living with the disease. The incidence rate is about 13.7 new cases per 100,000 people per year. But the story behind these numbers is more nuanced than they appear, because a significant portion of thyroid cancer diagnoses may reflect improved detection rather than a true increase in disease.
How Many People Get Thyroid Cancer
In the U.S., thyroid cancer accounts for an estimated 45,240 new diagnoses in 2026. As of 2023, approximately 1,035,274 people were living with the disease. Globally, the numbers are much larger: about 821,000 new cases were recorded in 2022, with nearly three-quarters of those occurring in Asia. Eastern Asia has the highest age-adjusted incidence rate of any region in the world.
The average age at diagnosis is 51, and women are almost three times more likely to develop thyroid cancer than men. This sex difference is one of the most striking in cancer epidemiology and holds true across countries and cancer subtypes.
Why Diagnoses Have Surged
Thyroid cancer incidence has increased roughly 250% since 1990, but the death rate has barely changed. That gap is a hallmark of what epidemiologists call overdiagnosis: detecting cancers through screening that would never have caused symptoms or shortened someone’s life. A 2025 study in JAMA Network Open estimated that between 72% and 94% of papillary thyroid cancers diagnosed from 1991 to 2019 were overdiagnosed.
The main driver is the widespread use of neck ultrasound, which can pick up tiny thyroid nodules that would otherwise go unnoticed. The researchers modeled what would happen if ultrasound use for nodules you can’t feel during a physical exam dropped by a third or by two-thirds. In those scenarios, diagnoses would have fallen 17% to 41% in 2019, while overall mortality would have shifted by less than 0.1%. In other words, many of the cancers being found and treated aren’t the ones killing people.
This doesn’t mean thyroid cancer is never serious. It means the headline numbers overstate how often the disease poses a real threat, and that some people undergo surgery and lifelong medication for a cancer that would have sat quietly in their thyroid for decades.
Types of Thyroid Cancer
Not all thyroid cancers behave the same way, and the type you have matters far more than the diagnosis itself.
- Papillary thyroid cancer accounts for 70% to 80% of all cases. It’s the type most commonly caught by ultrasound, tends to grow slowly, and has an excellent prognosis. It’s also the type most affected by overdiagnosis.
- Follicular thyroid cancer makes up 10% to 15% of cases. It also tends to have good outcomes, though it’s slightly more likely than papillary cancer to spread to other organs.
- Medullary thyroid cancer accounts for about 2% of cases. It arises from a different type of thyroid cell and sometimes runs in families through inherited genetic mutations.
- Anaplastic thyroid cancer is found in less than 2% of patients. It’s aggressive, grows quickly, and is far harder to treat. This is the type responsible for most thyroid cancer deaths, despite being the rarest.
Who Is Most at Risk
Being female and being between your 30s and 60s are the strongest demographic risk factors. Beyond that, several things can raise your chances. Radiation exposure, particularly to the head or neck during childhood, is one of the most well-established causes. This includes radiation therapy for childhood cancers like Hodgkin lymphoma as well as exposure from nuclear accidents. The younger you are when exposed and the higher the dose, the greater the risk. Radiation exposure in adulthood carries much less risk.
A family history of thyroid cancer and certain inherited genetic conditions also play a role, though hereditary cases likely account for only a small portion of diagnoses overall. Excess body weight and very low or very high iodine intake are additional factors, though their contribution is smaller.
What the Numbers Mean in Practice
If you’re trying to put your personal risk in perspective, an incidence rate of 13.7 per 100,000 means that in a group of 10,000 people followed for a year, roughly one or two would receive a thyroid cancer diagnosis. Your lifetime probability is higher, of course, but the vast majority of those diagnoses are the slow-growing papillary type with a very high survival rate.
The gap between how common thyroid cancer is and how dangerous it is remains wider than for almost any other cancer. Over a million Americans are living with the diagnosis, and the overwhelming majority will not die from it. The real challenge isn’t the disease itself for most patients. It’s navigating the anxiety of a cancer diagnosis when, in many cases, the most appropriate response may be monitoring rather than immediate treatment. Many medical centers now offer active surveillance as an option for very small, low-risk papillary thyroid cancers, allowing people to avoid surgery unless the tumor shows signs of growing.