Sickle cell disease is inherited
It is passed through hemoglobin gene copies inherited from biological parents. It is not contagious.
Understand • Test • Educate • Empower
About Sickle Cell Anemia
Explore how hemoglobin affects red blood cells, why some cells become rigid and curved, how sickle cell anemia is inherited, and what it means to carry sickle cell trait.
Trait and disease are different
HbAS usually means sickle cell trait, while HbSS is one form of sickle cell disease.
Testing identifies hemoglobin status
A blood test can identify hemoglobin type and help people understand inheritance.
Know when to seek urgent care
Learning emergency warning signs can help people living with sickle cell disease know when immediate evaluation may be needed.
Start with the basics
What is sickle cell anemia?
Sickle cell anemia, commonly written as HbSS, is an inherited blood condition in which the body makes hemoglobin S. Hemoglobin is the oxygen-carrying protein inside red blood cells.
Hemoglobin and red blood cells
Healthy red blood cells are typically flexible discs. They move through large and tiny blood vessels to deliver oxygen throughout the body. In sickle cell anemia, hemoglobin S can cause some red blood cells to become rigid and crescent-shaped, especially under stressful conditions.
These cells may break down sooner than normal red blood cells and can slow or block circulation. This can contribute to anemia, pain episodes and other complications that require medical care.
InheritedPassed through genes
HbSSTwo S gene copies
Not contagiousCannot spread person to person
Animated blood-flow lesson: normal cells move more freely; rigid sickled cells can
become caught or cluster in narrow vessels.
Know your hemoglobin status
Three important genetic outcomes
Every person receives one hemoglobin gene copy from each biological parent. The combination helps determine whether someone has typical hemoglobin, carries the trait, or has sickle cell anemia.
AA
HbAA: Typical hemoglobin
Two hemoglobin A gene copies—one inherited from each biological parent.
- Does not have sickle cell trait
- Does not have HbSS sickle cell anemia
- Passes an A gene copy to each child
AS
HbAS: Sickle cell trait
One hemoglobin A gene copy and one hemoglobin S gene copy.
- Also described as being a carrier
- Usually does not have the symptoms of HbSS
- Can pass either A or S to a child
SS
HbSS: Sickle cell anemia
Two hemoglobin S gene copies—one inherited from each biological parent.
- Produces predominantly hemoglobin S
- Can cause chronic anemia and pain episodes
- Requires ongoing specialized healthcare
Explore other types of sickle cell disease
HbSC
One hemoglobin S gene copy and one hemoglobin C gene copy. Symptoms and complications can still be serious.
HbS beta-zero thalassemia
Hemoglobin S is inherited with a beta-thalassemia gene that produces no normal beta-globin.
HbS beta-plus thalassemia
Hemoglobin S is inherited with a beta-thalassemia gene that produces a reduced amount of normal beta-globin.
Interactive inheritance lesson
Build a Punnett square
Select the hemoglobin status of each biological parent. The square automatically combines the possible gene copies and calculates the chance for each outcome.
HbAS × HbAS
Trait × TraitP1 ↓ P2 →
A
S
A
S
25%
HbAA · Typical hemoglobin
50%
HbAS · Sickle cell trait/carrier
25%
HbSS · Sickle cell anemia
What this cross means: When both biological parents have sickle cell trait,
each pregnancy has a 25% chance of HbAA, a 50% chance of HbAS and a 25% chance of HbSS.
Test what you learned
Five-question knowledge check
Select an answer to receive an immediate explanation.
1. Sickle cell trait is a mild form of sickle cell anemia.
False. HbAS trait and HbSS sickle cell anemia are different genetic states.
2. How many hemoglobin gene copies does a child inherit?
A child inherits two hemoglobin gene copies—one from each biological parent.
3. Which genotype usually represents sickle cell trait?
HbAS usually represents sickle cell trait: one A gene copy and one S gene copy.
4. When both biological parents have HbAS, what is the chance of HbSS in each pregnancy?
The chance is 25% for each pregnancy.
5. Does one child’s result change the probability for the next pregnancy?
No. Each pregnancy is a new and independent inheritance event.
Score: 0 of 5 answered correctly
Real voices. Real care experiences.
Listen to people who know sickle cell
Personal stories help visitors understand both the strength of people living with sickle cell anemia and the serious consequences of delayed, dismissive or biased healthcare.
Success is more than surviving
People living with sickle cell anemia are students, parents, professionals, artists, advocates and leaders. Their diagnosis is part of their story, but it does not define their potential.
Emergency-room experiences matter
Severe pain must be taken seriously. Listening, timely assessment, respectful communication and following an individualized care plan can change a frightening encounter into compassionate care.
Content note: These videos discuss illness, severe pain, hospitalization and unequal treatment.
They are included to build understanding, empathy and better care—not to sensationalize patient experiences.
Recognize an emergency
When to seek immediate medical care
Some sickle cell complications can become life-threatening quickly. Do not wait for symptoms to become unbearable.
Fever
A temperature of 101.3°F (38.5°C) or higher can signal a serious infection and needs urgent evaluation.
Chest or breathing symptoms
Chest pain, coughing, fever, shortness of breath or difficulty breathing may indicate acute chest syndrome.
Stroke warning signs
Sudden weakness, facial drooping, numbness, severe headache, confusion, speech difficulty or vision changes require emergency help.
Severe or unusual pain
Seek care when pain is severe, rapidly worsening, different from usual pain or not responding to the home plan.
Sudden extreme weakness
Paleness, fainting, unusual sleepiness, fast heartbeat or a rapidly enlarging abdomen may signal severe anemia or splenic sequestration.
Prolonged painful erection
Priapism lasting four hours is a medical emergency; earlier medical advice may be needed based on the individual care plan.
Call 911 for stroke symptoms, severe breathing difficulty, loss of consciousness or another life-threatening emergency.Follow the individual’s hematology team instructions and emergency plan whenever available.
Call 911
Tools for real-life care
Prepare, communicate and advocate
Create a personal emergency card, complete an ER checklist and prepare a clear care statement.
Build my sickle cell emergency card
Enter only information you are comfortable storing or printing on your own device.
Sickle Cell Emergency Card
Please listen to and believe my description of pain.
Date of birthNot entered
DiagnosisNot entered
HematologyNot entered
AllergiesNot entered
Emergency contactNot entered
Pain planNot entered
Interactive ER checklist
Check each item as it is placed in your emergency folder, phone or travel bag.
0 of 10 prepared
Build my care voice
Create a concise statement for a severe-pain visit. Edit it to match your own care plan.
I live with sickle cell anemia. My current pain is 10 out of 10 and is different from my usual baseline. Please review my individualized pain plan and contact my hematology team. Please reassess my pain after treatment.
Share your sickle cell story
Invite community members to submit a written, audio or video story through a consent-based review process.
Recommended submission choices:
Written story · audio story · video story · anonymous option · permission to publish name/photo · permission to edit for clarity.
Written story · audio story · video story · anonymous option · permission to publish name/photo · permission to edit for clarity.
No story should be published without documented permission and editorial review.
Prepare and advocate
A better emergency-room experience
Preparation supports communication, but patients should never have to prove that their pain is real or earn compassionate treatment.
Patient and family ER checklist
Keep these items together digitally or in a small emergency folder.
- ✓Individualized pain plan
Include usual medications, doses, allergies and approaches that have or have not worked. - ✓Current medication list
Include disease-modifying medicines, recent doses and pharmacy information. - ✓Hematology contacts
Carry the specialist’s name, office number and after-hours instructions. - ✓Baseline information
Know typical hemoglobin, oxygen saturation and relevant transfusion or antibody history when available. - ✓Medical identification
Use a wallet card, phone medical ID or bracelet that identifies sickle cell anemia. - ✓Support person
When possible, bring someone who can communicate changes and support informed decision-making.
What compassionate clinical care looks like
High-quality emergency care combines urgency, listening, individualized treatment and repeated reassessment.
Believe the patientPain is subjective. Respect the patient’s report, knowledge and prior response to treatment.
Assess promptlyEvaluate pain and screen for fever, acute chest syndrome, stroke and other complications without unnecessary delay.
Use the care planFollow an individualized pain plan when available rather than restarting the treatment conversation from zero.
Treat and reassessProvide timely analgesia and reassess response and safety repeatedly, adjusting treatment as clinically appropriate.
Communicate respectfullyExplain decisions, avoid stigmatizing language and include the patient in the care plan.
Plan the transitionCoordinate discharge, admission or specialist follow-up with clear return precautions.
Quality principle: ASH guidance supports rapid assessment and treatment of acute sickle cell pain, with individualized dosing when a plan is available and ongoing reassessment.
The diagnosis is not the limit
Living fully with sickle cell
Education about emergencies must be balanced with stories of identity, achievement, joy and possibility.
Education
Planning, accommodations and support can help students pursue their goals.
Career
People living with sickle cell are professionals, business owners and leaders.
Family
Individualized medical guidance can support parenting and family planning.
Travel
Preparation, hydration and access to care can support safer travel experiences.
Creativity
Artists and storytellers use lived experience to educate and inspire.
Relationships
Understanding and communication strengthen supportive relationships.
Faith & community
Community networks can offer practical, emotional and spiritual support.
Advocacy
Lived experience can influence awareness, policy and better healthcare.
Advancing hope through research
Research & Clinical Trial Opportunities
Clinical research helps scientists evaluate new medicines, treatments and approaches to care. Participation is always voluntary, and every study has its own eligibility requirements, potential benefits, risks and time commitments.
What is a clinical trial?
A clinical trial is a carefully designed research study involving people. Studies may evaluate a new treatment, compare care approaches, study long-term outcomes or explore ways to improve quality of life.
Questions to ask
- What is the purpose of the study?
- What would participation require?
- What are the possible risks and benefits?
- Which costs are covered by the study?
- Who should I contact with questions?
Talk with your care team
Your hematologist or qualified healthcare professional can help you understand whether a study may be appropriate for you and how participation could affect your current care.
Search trusted resources
Find current opportunities
Study availability and enrollment status can change. Use the official resources below to review current information and contact the study team directly for eligibility details.
Important: MBS Health Network and the Sickle Cell Hope Foundation do not determine eligibility, recommend a specific study or enroll participants through this webpage. Contact the listed research team and discuss participation with a qualified healthcare professional before making a decision.
Hope becomes action
Continue your journey with us
Education is the beginning. Connect with support, advocacy, community activities and ways to strengthen the mission.
Turn the cards over
Myths and facts
Click or tap each statement to reveal the explanation.
Myth
Sickle cell trait is a mild form of sickle cell anemia.
Fact
Trait and anemia are different genetic states.
HbAS means one A and one S gene copy. HbSS means two S gene copies.
Myth
If one child has HbSS, the next child cannot have it.
Fact
Every pregnancy is a new probability event.
The same genetic chances apply again for each pregnancy.
Myth
Sickle cell anemia can be caught from another person.
Fact
It is inherited, not contagious.
It is caused by gene copies inherited from biological parents.
Myth
You can always tell whether someone carries the trait.
Fact
A blood test is needed to know hemoglobin status.
Many carriers feel healthy and may not know they have HbAS.
Educational quality & transparency
Built around trusted sickle cell resources
This page is designed for community health education. Medical information is supported by recognized public-health and hematology resources, while interactive tools are educational and do not replace individualized medical care, diagnosis, treatment or genetic counseling.
Educational Review
Dr. Tanya Thompson, DHSc · Founder & President/CEO · MBS Health Network | Sickle Cell Hope Foundation
Last Reviewed: July 2026 · Next Scheduled Review: July 2027
Page experience updated August 10, 2026.
Primary reference resources
Use the official resources below for current disease information, research and clinical guidance.
Know your status. Know your options.
Hemoglobin testing and genetic counseling can help individuals and families understand sickle cell trait, inheritance and reproductive probabilities.
Connect With MBS Health Network
Educational information only. This page does not replace diagnosis, treatment, genetic counseling
or advice from a qualified healthcare professional. Interactive entries remain in the visitor’s browser and are not submitted to MBS Health Network.