Whiplash is a well-known neck injury most commonly associated with auto accidents. Millions of Americans suffer from whiplash each year, but the damage is still widely misunderstood. As an invisible ailment that can be tricky to diagnose, many people don’t take whiplash seriously or claim victims are exaggerating their pain.

Here are four surprising facts you may not have known about whiplash and why you should always see a doctor after a car accident:

1. Symptoms aren’t always immediate

Neck and shoulder pain are among the most frequent signs of whiplash immediately after an accident; however, whiplash symptoms aren’t always immediately apparent. The symptoms will usually show up within 24 hours of the accident but can sometimes occur days or even weeks later. Other common signs of whiplash can include:

  • Headaches
  • Dizziness
  • Blurred vision
  • Constant fatigue

2. It doesn’t take much force

You don’t need a high-speed collision to sustain a whiplash injury. Whiplash can occur even when a car travels at speeds as low as five mph. Any force that causes a rapid back-and-forth motion to your neck can result in whiplash injuries.

3. Some people are at higher risk of developing whiplash than others

Certain factors can put individuals at higher risk of developing whiplash-type injuries. If any of the following apply to you, you must have a doctor evaluate you after a collision:

  • You have a history of neck pain
  • You have had whiplash before
  • You are in a rear-end accident
  • You are a woman
  • You have a desk job

4. Rest isn’t always best for your neck injury

Though it can feel counterintuitive, most doctors will prescribe physical therapy exercises that encourage you to move your neck. Foam neck collars that hold the head in place may reduce some pain, but studies have shown keeping the neck still for long periods can decrease your muscle strength and delay your recovery.

Whiplash seems like a minor injury. But while most whiplash-sufferers will recover fully in three months, others are not as lucky. If you were recently involved in an accident, be sure to see a medical professional to ensure you get the proper treatment.