5 Warning Signs of Low Testosterone: What Every Man Needs to Know

If you’re constantly feeling tired and struggling with weight gain, you might be wondering if low testosterone is the culprit. 

And you could be right.

I call testosterone the hero hormone for guys because it influences energy levels, mood, body composition, and overall vitality. It's the first place you should look if you don't feel like yourself anymore.

Yet, many men suffering from low testosterone go undiagnosed because they rely solely on a lab result rather than paying attention to their symptoms.

In this article, we’ll break down five of the most common warning signs of low testosterone—beyond just looking at a number on a lab test. Let’s dive in.

Why Symptoms Matter More Than Just a Number

Before you rush into testosterone replacement therapy (TRT) or grab a T booster supplement, it’s essential to determine whether testosterone is truly the issue. The key? Look at both symptoms AND levels.

Most guys assume that if their bloodwork shows “normal” testosterone levels, they’re in the clear. But that’s not always the case. 

If you’re experiencing the following warning signs, your testosterone may still be too low for YOU—even if your doctor says otherwise.

1. Irritability & Mood Swings

Are you snapping at your family over minor annoyances? Yelling at other drivers? Feeling deep frustration over the news? If you’ve noticed increased irritability or mood swings, it could be due to dropping testosterone levels.

Low T isn’t just about aggression—it’s also linked to depression and emotional instability. Many men describe feeling "off" or not like themselves. If that sounds familiar, it’s time to check your hormones.

2. Poor Sleep Quality

We know that lack of sleep can cause low testosterone—after all, testosterone is primarily produced while you sleep. But did you know that low testosterone can also cause poor sleep?

If you’re tossing and turning, waking up frequently, or struggling to get deep, restorative sleep, your testosterone levels might be playing a role. Research shows that testosterone replacement therapy can improve sleep quality. And if you have sleep apnea, that’s an even bigger red flag for low T.

3. Changes in Body Composition

Less muscle, more belly fat. If your body is changing despite maintaining your usual diet and exercise routine, your testosterone levels may be declining.

Testosterone is essential for maintaining lean muscle mass and keeping fat levels in check. A sudden increase in belly fat or difficulty building muscle could be a clear sign that something is off hormonally.

4. Low Drive—In & Out of the Bedroom

One of the most noticeable symptoms of low T is a drop in drive—and not just in terms of sex.

Low testosterone can also zap your motivation for work, fitness, and hobbies. Many men describe this as "low energy," but it’s more than that. It’s a lack of interest in things that once excited them. 

If you find yourself uninterested in sex, business growth, or even activities you used to love, your testosterone could be to blame.

5. High Blood Sugar & Insulin Resistance

This is a big one. If your blood sugar levels are creeping up—whether it’s prediabetes or full-blown type 2 diabetes—you’re at a higher risk for low testosterone.

Insulin resistance (which leads to high blood sugar) and low testosterone go hand in hand. Studies show that men with diabetes often have significantly lower testosterone levels. The worse your blood sugar control, the lower your testosterone is likely to be.

The good news? Optimizing testosterone often helps regulate blood sugar levels, improving metabolic health overall.

Your Doctor Might Say You’re “Normal” – But Are You?

Here’s why symptoms matter even more than a single lab result.

Let’s say your doctor checked your total testosterone 10 years ago and it was 600—a solid level. Now, you’re noticing some or all of these symptoms, so you ask your doctor to retest your levels. This time, your total T comes back at 325.

Your doctor might say, “See, it’s still within the normal range.” 

But what they’re missing is that you’ve experienced a nearly 50% drop in testosterone in just 10 years—and your symptoms are proof that it’s affecting your health.

Even if a number falls within a “normal” range, a significant decline is not normal for you. And that’s what matters most.

Final Thoughts: Take Action Now

If you’re experiencing these warning signs, don’t ignore them. Your testosterone levels may be declining—even if your doctor says they’re “normal.”

You don’t have to rely on medications right away. There are natural strategies to optimize testosterone before considering TRT, including diet, exercise, sleep improvements, and lifestyle changes. My clients experience an average 70% increase in total testosterone within three months using this approach.

If you’re ready to take control of your health and performance, start by assessing your symptoms and then get the blood work to back it up.