Sleep deprivation, smoking and alcohol are three habits that hinder your health and silently raise your risk of chronic disease. If you want to feel better, think clearer and protect your heart, understanding how these behaviors affect your body is the first step toward lasting change.
This lesson closes module two with a practical look at why these habits damage you, how to recognize the triggers that pull you back, and what tools, like resilience and a support group, can help you break the cycle.
Why does staying up late hurt your health?
When you skip sleep, your body releases more ghrelin, the hunger hormone, which raises your risk of overweight and obesity the next day [01:00]. But the consequences go far beyond appetite.
During deep sleep, your brain clears amyloid proteins, a by-product of daily activity. If you don't sleep enough, these proteins build up in your central nervous system and have been linked to dementia and Alzheimer's [01:30]. Poor sleep also fuels depression, anxiety, and doubles your risk of heart disease and high blood pressure [02:15]. On top of that, your immune system weakens, leaving you exposed to bacterial and viral infections.
¿Why can't I fall asleep after using my phone? Electronic devices emit blue light, which blocks the release of melatonin, the hormone that signals your brain it's time to sleep. Stay off screens at least 30 minutes before bed.
How can you sleep better tonight?
Small rituals make a measurable difference. Try these habits to improve your rest:
- Sleep in a dark environment so your brain can release melatonin naturally.
- Avoid screens, TV and phones at least 30 minutes before bed.
- Keep your bed only for sleeping, not for eating or working.
- Go to bed and wake up at the same time, even on weekends, because your body loves rituals.
- Use breathing, meditation, body scans or soothing music if you struggle to fall asleep.
And here's the interesting part: consistency matters more than duration. Your body responds to predictable schedules.
What does smoking really do to your body?
Smoking is the leading cause of lung cancer, responsible for 80% to 90% of all cases [03:45]. The damage doesn't stop in your lungs.
Cigarette smoke destroys the alveoli, the tiny sacs in your lungs that exchange oxygen and carbon dioxide, which is why smoking is tied to chronic obstructive pulmonary diseases like emphysema. It also accelerates atherosclerosis, raises blood pressure and harms your cardiovascular system overall.
If you're planning to have a baby, smoking reduces oxygen flow to your reproductive organs, lowering fertility. And like poor sleep, it weakens your immune defenses against infections.
How does alcohol damage your liver and brain?
Alcohol is highly toxic to your liver, and chronic drinking leads to two main conditions you should know by name [05:30].
The first is steatosis, also called fatty liver, where fat cells accumulate and the liver becomes enlarged. The second is cirrhosis, in which alcohol toxins damage liver cells so severely that healthy tissue is replaced by scar tissue, and the organ loses its ability to filter blood.
Alcohol is also a leading cause of cancer throughout the digestive tract, contributes to high blood pressure and atherosclerosis, and causes cognitive impairment that makes focusing, problem-solving and memorizing harder over time.
¿What is cirrhosis? It's liver damage caused by long-term alcohol use, where healthy cells are replaced by scar tissue and the liver can no longer filter your blood properly.
What triggers send you back to old habits?
Relapses are normal, and recognizing your triggers makes them easier to manage. There are three types you should watch for [07:50]:
- Physical trigger: seeing someone smoke or drink in front of you can spark the urge to do the same.
- Emotional trigger: stress, sadness or frustration often pushes you toward old comforts.
- Behavioral trigger: rituals like a cigarette with coffee or a drink after lunch tie the habit to a specific moment of your day.
The good news? You can replace these rituals with healthier ones that still give you that sense of routine, like a walk after lunch or a cup of tea while you read.
Why is resilience the key to changing habits?
Resilience is your power to overcome difficulties, and it's what carries you through the hardest part of behavior change [09:10]. You can't control what other people do or what life throws at you, but you can control your response, and you can control yourself.
A support group multiplies that power. Family, friends or classmates going through the same process remind you that change is possible and that you don't have to do it alone. Be patient with yourself, non-judgmental, and remember what inspired you to start.
Your homework: reflect on a challenging time
Think about a difficult moment in your life and answer these questions in writing or with someone you trust:
- What was the most difficult aspect of that time?
- How did you cope with the difficulties?
- Who was your support group, friends, family, mentors?
- What mindset helped you overcome the challenges?
- Which character strengths from the previous class showed up when you needed them most?
Sharing your experience, even when it feels private, can help someone else change their lifestyle and become healthier. Drop your reflection in the comments and keep the conversation going.
