Common injuries in California accident claims

Two claims with the same accident and different injuries are worked very differently. The injury decides what has to be proven, how long the case takes, and how much of the fight is about causation. These pages explain the injuries that come up most, in plain terms, and how each one factors into a claim.

It is general information, not legal advice, and it is not medical advice. For a diagnosis or treatment, see a doctor.

What every injury claim has to establish

• The injury is real and documented. Objective findings — a fracture on an X-ray, a positive nerve study, a surgical report — carry the most weight. Injuries known from symptoms alone need a consistent record.
• The accident caused it. The medical records should connect this injury to this event, and address any pre-existing condition in the same area.
• The treatment made sense. Care that follows medical recommendations supports the claim. Care that looks driven by the lawsuit undermines it.
• The lasting effect is described. What the person can no longer do, what future care is likely, and how work and daily life changed.

Pre-existing conditions and vulnerability

Two rules matter across every injury type. First, aggravation: if an accident makes an existing condition worse, the responsible party owes the difference. Second, the eggshell-plaintiff rule: a defendant takes the victim as they are, so an unusually susceptible person still recovers for the full injury the accident caused.

Sources: CACI No. 3927 (aggravation of a pre-existing condition); CACI No. 3928 (unusually susceptible plaintiff). CACI citations are to the Judicial Council of California Civil Jury Instructions (2026 edition).

The injuries

Common questions

Why does the type of injury matter so much to a claim?

Because it drives how the injury is proven. An injury that shows on imaging or a nerve study is documented objectively. An injury known mainly from the patient's report — soft tissue, headache, pain — has to be built from a consistent treatment record and functional limits.

I had a prior injury to the same body part. Does that end my claim?

No. If an accident aggravates a pre-existing condition, the person who caused the accident is responsible for the worsening. California juries are instructed on this. The prior condition matters for what the records have to show, not for whether a claim exists.

What is the "eggshell plaintiff" rule?

A defendant takes the injured person as they find them. If someone was unusually vulnerable to harm and the accident caused a worse injury than it would in an average person, the defendant is still responsible for the full injury.

Does a gap in treatment hurt my claim?

It can. Large unexplained gaps let the defense argue you healed or the injury was minor. Consistent, doctor-recommended care — and a documented reason for any break, such as cost or waiting for authorization — keeps the record intact.