Test It Tuesday: Fibrinogen – The Overlooked Inflammation Marker

You’ve probably heard of inflammation, and maybe even labs like CRP or ESR. But what if I told you there’s another marker—less commonly tested—that could explain chronic pain, fatigue, and cardiovascular risk?

It’s called fibrinogen.

Fibrinogen is a protein involved in blood clotting, but it also plays a major role in inflammation.

When levels are elevated, it thickens the blood, reduces oxygen delivery to tissues, and contributes to the sticky, inflammatory environment that can fuel joint pain, headaches, fatigue, and even autoimmune flares.

In my practice, I look at fibrinogen when:

Pain and inflammation don’t resolve with basic treatment

There’s a history of heart disease, stroke, or blood clots

Lab tests show sluggish healing or tissue hypoxia

Patients have elevated D-dimer, CRP, or ESR

There are signs of hypercoagulation or long COVID

Optimal functional range: 200–300 mg/dL

Many labs don’t flag it until it’s over 400—but I’m looking at function, not just pathology.

When we catch fibrinogen early and bring it into balance through diet, lifestyle, and supplements like nattokinase or omega-3s, it can dramatically shift how a person feels—and heals.

Don’t guess. Test.