Elevated Alkaline Phosphatase: Causes and What to Do Next

You're looking at your blood test results and see alkaline phosphatase (ALP) is flagged as high. What does this mean? Is your liver failing? Do you have bone disease? Before you worry, understand that elevated ALP is very common and has many causes—some serious, but many benign and easily addressed.

This guide will explain what ALP is, why it might be elevated, what your doctor will check next, and what you can do.

Normal range: Typically 30-120 U/L (varies by lab and age)

Alkaline phosphatase (ALP) is an enzyme found throughout your body, but primarily in:

• The liver (specifically the cells lining the bile ducts)
• The bones (cells involved in bone formation called osteoblasts)
• Smaller amounts in: intestines, kidneys, placenta (during pregnancy)

Enzymes are proteins that speed up chemical reactions. ALP helps with:

• Bone growth and remodeling (especially in children and teens)
• Bile flow (helping digest fats)
• Liver function

When liver cells (specifically bile duct cells) or bone cells are stressed or damaged, they release more ALP into the bloodstream—this is what shows up as "elevated ALP" on blood tests.

This is the first diagnostic puzzle when ALP is high. Is the elevated ALP coming from your liver or your bones?

Clues It's Liver-Related

Elevated ALP is more likely from your liver if you also have:

• Elevated GGT (gamma-glutamyl transferase)—another liver enzyme
• Elevated bilirubin (causing jaundice/yellowing)
• Elevated ALT or AST (other liver enzymes)
• Symptoms like:
  • Jaundice (yellowing of skin/eyes)
  • Dark urine
  • Pale stools
  • Itching (bile salts in skin)
  • Nausea, abdominal pain
  • Fatigue

Clues It's Bone-Related

Elevated ALP is more likely from bone if:

• GGT is normal (or only mildly elevated)
• You have bone symptoms:
  • Bone pain
  • Fractures from minor injuries
  • Joint pain
• You're in a high-risk group:
  • Children/teenagers (growing bones)
  • Pregnant women (third trimester)
  • Post-menopausal women (bone loss)
  • People with known bone conditions

The Confirmatory Test: GGT

Your doctor will almost always order GGT alongside ALP. Here's why:

This simple test is usually enough to determine the source of elevated ALP.

Liver Causes

1. Bile Duct Obstruction (Cholestasis)

When bile can't flow from your liver to your gallbladder and intestines, ALP rises dramatically.

Causes of obstruction:

• Gallstones in the bile duct
• Pancreatic cancer or other tumors pressing on bile ducts
• Bile duct strictures (narrowing)
• Primary biliary cholangitis (autoimmune bile duct disease)
• Primary sclerosing cholangitis (inflammatory bile duct disease)

Symptoms:

• Jaundice (yellowing)
• Itching (often intense)
• Pale, clay-colored stools
• Dark urine
• Fatigue

2. Liver Diseases

Many liver conditions can elevate ALP:

• Hepatitis (viral, alcoholic, autoimmune)
• Cirrhosis (advanced liver scarring)
• Fatty liver disease (mild elevation)
• Liver cancer or metastases to the liver
• Drug-induced liver injury

3. Alcohol Use

Heavy alcohol use can cause:

• Fatty liver
• Alcoholic hepatitis
• Cirrhosis

All can elevate ALP, though ALT and AST are usually also elevated.

Bone Causes

1. Paget's Disease of Bone

This is the classic bone disease causing high ALP. Paget's disease causes abnormal bone remodeling—bones become enlarged and weakened.

Who gets it:

• Usually people over 50
• More common in men
• More common in people of European ancestry

Symptoms:

• Bone pain
• Bone deformities
• Fractures from minor injuries
• Hearing loss (if skull bones affected)
• Headaches

2. Bone Healing and Growth

Children and teens normally have higher ALP because their bones are actively growing. This is NOT a cause for concern.

Healing fractures also cause temporary ALP elevation.

3. Osteomalacia and Rickets

• Osteomalacia: Soft bones in adults (often from vitamin D deficiency)
• Rickets: Soft bones in children (vitamin D deficiency)

Both cause high ALP as bones try to remineralize.

4. Hyperparathyroidism

Overactive parathyroid glands cause:

• Calcium to be leached from bones
• Bone turnover increases
• ALP rises

5. Bone Cancer and Metastases

Cancer that starts in bone (like osteosarcoma) or spreads to bone (from breast, prostate, lung) can cause very high ALP.

This is rare, but a reason very high ALP needs prompt evaluation.

6. Osteoporosis

Surprisingly, osteoporosis usually does NOT significantly elevate ALP. In fact, normal or low ALP with bone loss suggests low bone turnover.

Other Causes

1. Pregnancy

During pregnancy, especially the third trimester, ALP rises because:

• The placenta produces ALP
• Fetal bones are growing

Levels can reach 2-3 times normal—this is completely expected and not concerning.

2. Medications

Many medications can raise ALP:

Always tell your doctor about all medications and supplements.

3. Hyperthyroidism

Overactive thyroid increases bone turnover, which can raise ALP.

4. Inflammatory Bowel Disease

Crohn's disease and ulcerative colitis can cause elevated ALP, sometimes from liver involvement (primary sclerosing cholangitis) and sometimes from bone loss associated with these conditions.

Elevated ALP is a clue, not a diagnosis. Your doctor will order additional tests to find the cause.

Essential Follow-up Tests

Additional Tests Depending on Suspected Cause

If liver disease suspected:

• Hepatitis viral panel
• Autoimmune liver disease markers
• Liver ultrasound or other imaging
• Sometimes liver biopsy

If bone disease suspected:

• Bone-specific ALP (more specific for bone)
• Bone mineral density scan (DEXA)
• X-rays of affected bones
• Sometimes bone scan

While elevated ALP itself isn't an emergency, certain situations need prompt attention:

Seek Prompt Care For:

• ALP over 500 U/L (significantly elevated)
• ALP elevation with jaundice (yellowing of skin/eyes)
• ALP elevation with severe itching
• ALP elevation with severe abdominal pain
• ALP elevation with confusion or extreme fatigue
• Known liver disease with sudden ALP rise
• Known cancer with new ALP elevation

Schedule Prompt Follow-up For:

• Any unexplained ALP elevation
• ALP that's rising over time on repeat testing
• ALP elevation with other abnormal liver tests
• Risk factors for liver disease (alcohol use, hepatitis, etc.)
• Risk factors for bone disease (family history, aging, etc.)

Treatment depends entirely on the underlying cause—there's no "treatment" for elevated ALP itself, only for what's causing it.

For Liver Causes

• Gallstones: May need gallbladder surgery or procedure to remove stones
• Hepatitis: Antiviral medications for viral hepatitis; alcohol cessation for alcoholic hepatitis
• Autoimmune liver disease: Immune-suppressing medications
• Cancer: Surgery, chemotherapy, or other treatments depending on type
• Fatty liver: Weight loss, diet changes, exercise, alcohol cessation

For Bone Causes

• Paget's disease: Bisphosphonate medications to slow bone turnover
• Vitamin D deficiency: Vitamin D supplementation
• Hyperparathyroidism: Surgery to remove overactive parathyroid gland(s)
• Bone cancer: Oncology treatment (surgery, chemo, radiation)
• Osteomalacia: Vitamin D and calcium supplementation

For Other Causes

• Pregnancy: No treatment needed—resolves after delivery
• Medications: Adjust or stop offending medication if possible

While waiting for your appointment:

1. Review Your Medications

Make a list of all:

• Prescription medications
• Over-the-counter drugs
• Supplements and vitamins
• Herbal remedies

Bring this to your appointment.

2. Assess Your Risk Factors

For liver disease:

• Alcohol intake (be honest)
• History of hepatitis
• Family history of liver disease
• Exposure to hepatotoxic chemicals
• Unprotected sex or tattoo/piercing (hepatitis risk)
• Fatty liver risk factors (obesity, diabetes)

For bone disease:

• Age and sex (postmenopausal women at higher risk)
• Family history of bone disease
• Unexplained fractures
• Bone pain
• Vitamin D deficiency risk (limited sun exposure, dark skin)

3. Track Your Symptoms

Note any:

• Jaundice or yellowing
• Itching (especially worse with heat)
• Pale or clay-colored stools
• Dark urine
• Bone pain (where, when, severity)
• Unusual fractures
• Abdominal pain

4. Don't Stop Medications

Unless your doctor tells you to, don't stop any medications. Some cause withdrawal or make your condition worse if stopped abruptly.

1. "What's causing my elevated ALP?"
2. "Is this coming from my liver or my bones?"
3. "What additional tests do I need?"
4. "How serious is this?"
5. "Do I need a specialist (gastroenterologist, hepatologist, endocrinologist)?"
6. "Should I stop any medications or supplements?"
7. "What symptoms should I watch for?"
8. "When should we recheck my levels?"
9. "What lifestyle changes do you recommend?"
10. "Is this a chronic condition or can it be cured?"

In Children

Children normally have higher ALP due to bone growth. "Elevated" ALP in a child might be completely normal for their age. Pediatric reference ranges account for this.

In Pregnancy

ALP rises in pregnancy, especially the third trimester. Levels 2-3 times the adult normal range are expected and not concerning.

However, if ALP is extremely high or accompanied by itching or jaundice, your doctor will check for:

• Intrahepatic cholestasis of pregnancy (requires monitoring)
• Gallstones (more common in pregnancy)
• Liver problems unrelated to pregnancy

In Older Adults

In older adults, elevated ALP is more concerning for:

• Occult liver disease
• Paget's disease of bone
• Bone metastases from cancer
• Drug-induced liver injury (polypharmacy)

Thorough evaluation is especially important in this age group.

Elevated alkaline phosphatase is a finding, not a diagnosis. It tells you something is going on with your liver or bones (or occasionally other organs), but additional testing is needed to identify the specific cause.

Most common scenarios:

• Mild elevation with normal GGT: Probably bone-related or medication effect
• Elevated with high GGT: Probably liver-related
• Very high elevation: Needs prompt evaluation for serious liver or bone disease

The key is finding the cause:

1. Don't panic—most causes are identifiable and treatable
2. Get the recommended follow-up tests
3. Work with your doctor to identify what's causing the elevation
4. Treat the underlying condition
5. Recheck to confirm improvement

Elevated ALP is your body's signal that something needs attention. Listen to it, get the right tests, and work with your healthcare team to address whatever is causing the elevation. With proper diagnosis and treatment, most causes of elevated ALP can be effectively managed.

Related articles on WellAlly:

• Understanding Your Liver Function Tests
• Elevated Liver Enzymes: Causes and Treatment
• Complete Guide to Bone Health
• GGT Blood Test: What It Means