You’ve been feeling off for days—drained, warm, not quite yourself. That nagging heat? It could be a constant low-grade fever. And it’s not going away. Is it harmless, or something more? Don’t stress—we’ll walk you through what it means, what to watch for, and when it’s time to get help that actually helps.

What Is Considered a Low-Grade Fever?

Not every rise in body temperature means something serious. But even a small bump can mean your body is fighting something.

Here’s the general rule:

• Normal body temp: Around 98.6°F (37°C)
• Low-grade fever: Between 99.1°F and 100.4°F (37.3°C – 38°C)

So if your thermometer reads 99.5°F and stays there for a few days, you’re in low-grade fever territory. If it keeps hanging around, that’s when the “persistent” part comes in.

Common Causes of Persistent Low-Grade Fever in Adults

Why won’t it go away? That’s the big question.

Let’s look at what could be behind a fever that sticks around for more than a couple of days:

• Viral infections: A cold, flu, or COVID-19 can cause a fever that lingers.
• Urinary tract infections (UTIs): Especially in adults, UTIs may not cause pain but still cause a fever.
• Chronic inflammation: Conditions like rheumatoid arthritis or lupus can spark an ongoing immune response.
• Hidden infections: Think sinus infections, dental abscesses, or even an infected wound.
• Thyroid problems: An overactive thyroid (hyperthyroidism) speeds up your body, which may lead to a low-grade fever.
• Medications: Some meds—like antibiotics or those for high blood pressure—can trigger a mild fever.
• Cancers: Certain types, like lymphoma or leukemia, may present with persistent low fevers.
• Tuberculosis: Though less common now, TB still shows up, often as a low fever.

Each case is different. The important part? Pay attention to how you feel and what else is going on in your body.

When to See a Doctor

It’s easy to brush it off, but don’t ignore a low fever for a week—it could be a sign of something more serious.

Here’s when to make the call:

• Fever lasts more than 7 days
• You have chills, night sweats, or weight loss
• You’re extra tired or foggy
• New symptoms show up—rash, pain, cough, or swelling

Waiting too long can mean a small issue turns into something much bigger. In cases where you feel suddenly worse or symptoms spike overnight, consider heading to a 24-hour emergency care center.

You’ll get answers fast, and sometimes that peace of mind is worth it.

Diagnostic Tests and What to Expect

Don’t worry—testing doesn’t mean anything scary. It’s just how doctors put the puzzle pieces together.

Here’s what might happen during your visit:

• Physical exam: Your doctor checks your lungs, ears, throat, and belly.
• Blood tests: These tests check for any signs of infection or swelling in the body.
• Urine test: Helps find a UTI or kidney issue.
• X-ray or CT scan: To spot hidden infections or problems inside the body.
• COVID or flu test: Especially if you’ve had recent contact or symptoms.

You might not need every test. The goal is to rule out serious problems and figure out what’s causing the fever.

Treatment Options Based on Underlying Causes

Treatment isn’t one-size-fits-all. It depends on what’s behind the fever.

Here’s how doctors might respond:

• Infections
  • Viral: Rest, fluids, and fever reducers.
  • Bacterial: Antibiotics and follow-up testing.
• Autoimmune conditions
  • Anti-inflammatory medication
  • Possible referral to a specialist
• Medication side effects
  • Stopping or switching the drug
  • Monitoring your symptoms closely
• Cancer or chronic disease
  • Referral to an oncologist or specialist
  • Targeted treatment based on type and stage

If your symptoms get worse fast, you might need urgent treatment. Don’t wait it out—getting checked early can make all the difference.

Home Care and Lifestyle Tips

While doctors sort out the cause, there’s still a lot you can do at home to feel better and support your body.

Try these simple changes:

• Rest: Give your body time to heal. Don’t push yourself.
• Stay hydrated: Fever pulls moisture from your body. Sip water, broth, or herbal tea.
• Eat light, healthy meals: Focus on fruit, veggies, and easy-to-digest proteins.
• Use cool compresses: A damp cloth on your forehead can help bring the temperature down.
• Track your temperature: Use a thermometer once or twice a day to monitor changes.

Also, keep a notebook of your symptoms. Write down when they start, what gets better or worse, and how long they last. That info helps your doctor help you faster.

Final Thoughts

Don’t brush off that lingering heat—your body’s trying to tell you something. When it comes to answers, quick care makes all the difference. Express Emergency Room Temple is ready 24/7 to guide you from worry to relief. Walk in anytime, no appointment needed. You deserve care that listens, acts fast, and helps you heal right.