LabInformationLab tests, explained

Lactose Tolerance Test in California

Below is a plain-language overview of the lactose tolerance test. The lactose tolerance test checks how well your body digests lactose, the sugar found in milk and dairy products. It is usually ordered when a person has bloating, gas, diarrhea, or cramping after eating dairy, to see whether those symptoms come from trouble breaking down lactose. Across California, part of Pacific, the lactose tolerance test can be ordered directly and collected at a certified site — no referral required.

Sample type
blood
Category
General Wellness
Turnaround
1-3 business days
Price
$159
Referral
Not required

The lactose tolerance test checks how well your body digests lactose, the sugar found in milk and dairy products. It is usually ordered when a person has bloating, gas, diarrhea, or cramping after eating dairy, to see whether those symptoms come from trouble breaking down lactose.

What it measures

  • Blood glucose (before drink) — Your starting blood sugar level, used as a baseline.
  • Blood glucose (after drink) — Blood sugar measured at set times after you drink a lactose solution.
  • Change in blood glucose — A small rise suggests lactose is not being broken down and absorbed well.
  • Symptoms during test — Bloating, gas, cramps, or diarrhea noted by staff during the test.

Who it is for

It is typically ordered by a primary care clinician or a digestive specialist for adults and children who have recurring stomach symptoms after consuming dairy. It may also be used when other causes of similar symptoms have been ruled out.

Preparation

You usually need to fast for about 8 hours before the test, and you may be asked to avoid dairy and strenuous exercise beforehand. Follow the exact instructions from your clinician or lab.

Results and what they mean

Results are reported as blood glucose values over time along with any symptoms you had. A clinician interprets these together with your history; a small rise in glucose plus symptoms can point toward lactose intolerance. This is general information, not medical advice, and only your clinician can explain what your results mean for you.

Requesting the Lactose Tolerance Test in California

Order online, choose a certified collection site in California, and review results through a secure portal. No referral is required, and orders are processed confidentially. With coastal metros, inland towns, and rural counties with very different access to testing, it pays to schedule your collection in advance.

Frequently asked questions

Does the test hurt?

You will feel a brief pinch each time blood is drawn, and you drink a sweet lactose solution at the start. Most people tolerate the test well.

How long does it take?

The visit often lasts about 2 hours because blood is drawn several times after the drink. Plan to stay at the lab for the full period.

Can I eat during the test?

No. You usually cannot eat or drink anything except water during the test, since food would change your blood glucose readings.

What if I feel sick during the test?

Tell the staff right away. They can note your symptoms and may stop the test if you feel too uncomfortable.

Lactose Tolerance Test by city in California

All testing in California →   Full Lactose Tolerance Test guide →