Is it true that many thyroid cancers show no symptoms at all in the early stages?

Okay, let's talk about this issue that many people are concerned about.

You've hit the nail on the head: The vast majority of early-stage thyroid cancers are indeed "silent"

I can tell you with great certainty that yes, the vast majority of thyroid cancers cause absolutely no sensation or symptoms in their early stages.

Many people feel terrified when they hear the word "cancer," associating it with pain, weight loss, loss of appetite, and so on. But thyroid cancer is an exception. It's famously known as a "lazy cancer" or "indolent cancer" within the cancer family, especially when it's just beginning.

Why is this? Think of it like a "quiet tenant"

Our thyroid gland is shaped like a butterfly, sitting in front of the windpipe in the neck. Early-stage thyroid cancer is usually just a very small nodule (a little lump) with these characteristics:

Slow Growth: The most common types of thyroid cancer (like papillary carcinoma) grow extremely slowly. They may show little change for years, even over a decade. It's like a quiet tenant, causing no disturbance and just sitting there growing slowly.
Location Isn't Problematic: In the early stages, this small nodule is tiny and buried deep within the thyroid tissue. It doesn't press on the nearby windpipe to cause breathing difficulties, nor does it touch the nerves controlling the vocal cords to cause hoarseness. It also doesn't affect thyroid function, so it won't cause heart palpitations, heat intolerance, or cold intolerance.
No Pain or Itchiness: It doesn't cause any pain itself.

Therefore, before it "makes a big fuss," it's almost impossible to detect its presence through your own sensations.

If there are no symptoms, how do people usually discover it?

This is precisely the key point. The increasing detection rate of thyroid cancer today isn't because it's becoming more common, but because our diagnostic methods have improved. The vast majority of early-stage thyroid cancers are "accidentally" discovered under the following circumstances:

Physical Exams Play a Major Role: This is the primary reason. Many people undergo a neck ultrasound (color Doppler) during their annual workplace checkup or personal health screening. This ultrasound acts like a high-precision radar, clearly imaging even tiny nodules just a few millimeters in size within the thyroid. If the doctor sees suspicious features suggesting risk, they will recommend further tests (like a biopsy) for a definitive diagnosis.
"Incidental" Discovery: Some people get a CT or MRI scan for neck discomfort or to check neck blood vessels, and the doctor "incidentally" spots a suspicious shadow in the thyroid.
Self-Detection (Less Common): Unless someone is very thin with a long neck, or the nodule happens to be in a very superficial position, it's difficult to feel it yourself in the early stages. By the time a lump is clearly palpable, it's often no longer considered very early.

So, what should we ordinary people do?

Understanding the above points tells you what to do:

The Most Crucial Point: Don't Panic! Even if a thyroid nodule is found during a checkup, over 90%-95% are benign. Even if it unfortunately is thyroid cancer, the vast majority are "lazy cancers" with an excellent prognosis that are curable. With proper treatment, they typically have little impact on daily life or lifespan. So, don't scare yourself.
Add a "Neck Ultrasound" to Your Checkup Routine: This is the most effective, simplest, and radiation-free way to detect early thyroid cancer. It's recommended for adults, especially women (who have a higher incidence rate than men), to have one every one to two years.
Be Aware of "Delayed Signals": While there are no symptoms early on, if the tumor grows larger, it will eventually give itself away. Be alert and see a doctor promptly if you experience:
- Feeling a rapidly growing lump in the front of your neck.
- Unexplained hoarseness that persists and doesn't improve.
- Feeling difficulty swallowing, a sense of pressure, or breathing difficulties.
- Persistent dry cough not caused by a cold or bronchitis.

To Summarize

Yes, early-stage thyroid cancer is essentially "silent," causing no symptoms.
Detection relies primarily on "neck ultrasound" during checkups, not on feeling symptoms.
Don't overreact if something is found; the vast majority are benign nodules, and even if it's cancer, it's mostly a curable "lazy cancer."
Regular checkups are key, while also paying attention to any "delayed" warning signals from your body.

I hope this explanation helps you understand that when it comes to thyroid cancer, we need to take it seriously (through checkups) without excessive fear.