While regaling you with daring 
stories from her youth,

it might be hard to believe your 
grandmother used to be a trapeze artist.

However, the bad backs, elbow pain, 
and creaky knees so common in older people

is more than just “old age."

In fact, the source of this stiffness 
plagues many young people as well.

The culprit is arthritis:

a condition that causes inflammation 
and pain in the joints

of over 90 million people 
in the U.S. alone.

But are stiff, creaky joints 
really inevitable?

What makes arthritis so pervasive,

and why haven’t we found a cure for 
this widespread condition?

The first hurdle is that arthritis 
is actually a spectrum

of over 100 different arthritic 
conditions.

All these conditions share symptoms 
of joint pain and inflammation,

but the origin and severity of those 
symptoms vary widely.

Even the most common type, 
osteoarthritis,

is trickier to prevent than 
one might think.

It’s a general misconception that 
arthritis is confined to old age.

The origins of osteoarthritis can often 
be traced to a patient’s early life,

from any seemingly ordinary joint injury.

Following impact, immune cells rush in 
to help clean and repair the damaged site

and begin pumping out enzymes,

including matrix metalloproteinases 
and aggrecanases.

These enzymes clear out the damaged 
tissue and contribute to inflammation.

But while this rapid swelling helps 
protect the joint during recovery,

inadequately healed tissue can cause these
immune cells to overstay their welcome.

The continuing flood of enzymes starts 
to degrade the cartilage,

weakening the joint and leading 
to arthritis later on.

Not all forms of arthritis can simply 
be traced to an old sports injury.

Take rheumatoid arthritis, which 
affects 1.3 million U.S. adults.

This condition is actually an 
autoimmune disease

in which autoantibodies target 
natively produced proteins,

some of which are secreted 
by cartilage cells.

We still don’t know what 
causes this behavior,

but the result is that the body treats 
joint tissue like a foreign invader.

Immune cells infiltrate the joint despite 
there being no tissue damage to repair.

This response leads to chronic 
inflammation,

which destroys bone and cartilage.

Yet another condition, 
spondyloarthritis,

has similarities to both of the 
conditions we’ve covered.

Patients experience continuous 
inflammation in the joints

and at the sites where ligaments and 
tendons attach to bones,

even without any initial injury.

This leads to the flood of enzymes and 
degradation seen in osteoarthritis,

but is driven by different inflammatory 
proteins called cytokines.

As the enzymes eat away at cartilage,

the body attempts to stabilize smaller 
joints by fusing them together.

This process sometimes leads to 
outgrowths called bone spurs,

which also cause intense stiffness 
and joint pain.

With so many factors causing arthritis,

our current treatments are tailored 
to tackle specific symptoms

rather than underlying causes.

These range from promising 
MACI techniques,

which harvest cells from small pieces 
of cartilage to grow replacement tissue.

To a technique called microfracture,

where surgeons create small 
holes in the bone,

allowing bone marrow stem cells to 
leak out and form new cartilage.

As a last resort,

people with withered cartilage can 
even undergo full joint replacements.

But outside these drastic measures,

the underlying drivers of 
autoimmune arthritis

still present a unique 
treatment challenge.

Scientists are making progress with 
therapies that block TNF-alpha,

one of the primary proteins causing 
inflammation in rheumatoid arthritis.

But even this approach only treats the 
symptoms of the condition, not the cause.

In the meantime, some of our best defenses
against arthritis are lifestyle choices:

maintaining a healthy weight to 
take pressure off joints,

low-impact exercises like yoga or cycling,
and avoiding smoking.

These arthritis-fighting behaviors 
can help us lead longer lives

as we continue to research 
cures and treatments

for the huge diversity of 
arthritic conditions.