Tuesday, December 2, 2025

Alzheimer’s Disease: Causes, Symptoms, Diagnosis and Management

Alzheimer’s Disease: Causes, Symptoms, Diagnosis, and Management

What is Alzheimer’s disease?

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and one of the most common cause of dementia all over the world. It primarily affects memory, thinking, behavior, and the ability to perform daily activities. The disease gradually worsens over time, leading to severe cognitive decline and dependence on caregivers.


Introduction

First described by Dr. Alois Alzheimer in 1906, Alzheimer’s disease is characterized by abnormal protein deposits in the brain—amyloid plaques and neurofibrillary tangles (tau protein). These changes damage neurons, disrupt communication between brain cells, and eventually lead to brain shrinkage.

It usually affects people above 65 years, but early-onset Alzheimer’s can occur before age 60.


Causes and Risk Factors


The exact cause is not fully understood, but several factors contribute:

1. Age

The biggest risk factor. Risk doubles every 5 years after age 65.


2. Genetics

Family history increases risk.

Certain genes like APOE-ε4 are associated with higher risk.


3. Abnormal Proteins

Amyloid plaques

Tau tangles


4. Lifestyle Factors

  • Sedentary lifestyle
  • Poor diet
  • Smoking
  • Excessive alcohol
  • Lack of mental and social activity



5. Medical Conditions

  • Hypertension
  • Diabetes
  • Obesity
  • High cholesterol
  • Previoushead injury


Symptoms


Alzheimer’s is gradual. Symptoms are typically divided into early, moderate, and late stages.


Early Stage

  • Mild forgetfulness (recent events, names)
  • Misplacing items
  • Difficulty planning or solving problems
  • Trouble finding words
  • Mood changes (irritability, anxiety)


Middle/Moderate Stage


  • Increased memory loss
  • Confusion about time and place
  • Difficulty with daily tasks (cooking, managing money)
  • Wandering or getting lost
  • Personality changes
  • Sleep disturbances

Late Stage

  • Inability to communicate
  • Difficulty swallowing
  • Complete dependence for daily activities
  • Loss of bladder and bowel control
  • Severe weight loss


Diagnosis


Diagnosis is clinical and involves:


1. Medical History & Cognitive Tests


Mini-Mental State Examination (MMSE)


Montreal Cognitive Assessment (MoCA)



2. Laboratory Tests


Blood tests to rule out other causes (thyroid, vitamin B12 deficiency)



3. Brain Imaging


MRI or CT scan


PET scan to detect amyloid or tau pathology (in special centres)


4. Neuropsychological Evaluation


Detailed assessment of memory and thinking skills


There is no single definitive test except a brain biopsy, which is not used in routine diagnosis.


Treatment and Management


There is no cure, but treatment can slow progression and improve quality of life.


Medications


1. Cholinesterase inhibitors:

Donepezil

Rivastigmine and

Galantamine

Help improve memory and cognition.


2. NMDA receptor antagonist:

Memantine

Used in moderate to severe stages.


3. Newer monoclonal antibodies (available in some countries)

Lecanemab

Aducanumab

These target amyloid proteins.


Non-Pharmacological Management


  • Cognitive stimulation therapy
  • Regular exercise
  • Social engagement
  • Healthy diet (Mediterranean diet)
  • Sleep hygiene
  • Maintaining routine and structured activities
  • Supportive Care
  • Caregiver education
  • Safety modifications at home
  • Behavioral management
  • Advanced care planning


Prevention and Lifestyle Measures


While the disease cannot always be prevented, certain habits lower risk:


  • Regular physical activity
  • Brain exercises (puzzles, reading, learning new skills)
  • Balanced diet rich in fruits, vegetables, whole grains
  • Social interaction
  • Good control of diabetes, hypertension, and cholesterol
  • Avoiding smoking and excessive alcohol


Conclusion


Alzheimer’s disease is a major global health challenge causing long-term disability and emotional burden. Early detection, appropriate management, supportive care, and healthy lifestyle choices can significantly improve the life of both patients and caregivers.

High blood pressure (hypertension): causes, symptoms, pathophysiology, investigations and treatment medications


Hypertension: A Comprehensive Guide
for Medical Students
(Harrison-Based Explanation)

Hypertension is one of the most common chronic medical conditions worldwide and a major preventable cause of cardiovascular, cerebrovascular, and renal disease. Although often silent, uncontrolled hypertension significantly increases the risk of stroke, myocardial infarction, heart failure, chronic kidney disease, and premature death. This article provides a clear, detailed, Harrison-style overview for MBBS Li students, interns, and early-career clinicians.



  • What is Hypertension?


Blood pressure (BP) is the force exerted by circulating blood on the arterial walls. Hypertension is diagnosed when this pressure is persistently elevated beyond established normal ranges.


  • BP Classification


Category Systolic BP and Diastolic BP


Normal blood pressure <120 and <80

Elevated 120–129 and <80

Stage 1 Hypertension 130–139 and diastolic 80–89 

Stage 2 Hypertension ≥140 and ≥90

Hypertensive Crisis ≥180 and ≥120



cardiovascular risk increases in a continuous, graded manner even within “high-normal” BP ranges


Types of Hypertension

hypertension and high blood pressure


1. Primary (Essential) Hypertension


Accounts for 90–95% of all cases.


No single cause; instead results from a combination of genetic, environmental, and lifestyle factors.



Major contributors:


Increased sympathetic nervous system (SNS) activity


Impaired pressure-natriuresis (kidneys retain sodium)


Endothelial dysfunction (reduced nitric oxide)


Obesity and insulin resistance


Family history



2. Secondary Hypertension


Occurs due to an underlying, identifiable cause. Suspect when BP is:


  1. Severe, resistant to >3 drugs
  2. Onset <30years or sudden after 55
  3. Associatedwith specific symptoms



what could cause high blood pressure?



  1. Renalparenchymal diseases (most common)
  2. Renovascularhypertension (RAS)
  3. Primary aldosteronism
  4. Pheochromocytoma
  5. Cushingsyndrome
  6. Hypo- or hyperthyroidism
  7. Obstructivesleep apnea
  8. Coarctationof the aorta
  9. Drugs: NSAIDs, oral contraceptives, steroids, decongestants, cocaine



  • Pathophysiology of Hypertension


Hypertension results from abnormalities in mechanisms regulating cardiac output and systemic vascular resistance.


1. RAAS Overactivity


Produces angiotensin II, a strong vasoconstrictor.


Stimulates aldosterone → sodium and water retention → ↑ blood volume.



2. Sympathetic Nervous System Activation


Increases heart rate, vasoconstriction, and cardiac output.


Seen in stress, obesity, sleep apnea.



3. Renal Regulation Problems


Kidneys fail to excrete sodium effectively.


Causes expansion of intravascular volume.



4. Endothelial Dysfunction


Reduced nitric oxide availability → vasoconstriction.



5. Vascular Remodeling


Structural changes in arteries increase peripheral resistance.




  • Clinical Features


Hypertension is mostly called the “silent killer” because patients often have no symptoms for years.


Some of the blood pressure too high symptoms are:


  1. Morningheadaches
  2. Dizziness
  3. Palpitations
  4. Fatigue
  5. Epistaxis
  6. Blurred vision



Signs of Target Organ Damage


Eyes: Retinopathy (AV nicking, hemorrhages, papilledema)


Heart: Left ventricular hypertrophy (LVH), HF


Brain: Stroke, TIA


Kidneys: Proteinuria, reduced GFR


Peripheral Arteries: Claudication




  • Evaluation of a Hypertensive Patient


A structured evaluation helps confirm diagnosis, look for secondary causes, and assess organ damage.


1. BP Measurement


Take ≥2 readings on at least 2 different visits.


Measure in both arms initially.


Ambulatory BP monitoring (ABPM) is preferred for borderline cases.



2. Routine Investigations


Fasting glucose, HbA1c


Lipid profile


Serum creatinine, eGFR


Electrolytes (especially potassium)


Complete blood count


Urinalysis (albumin/protein)


ECG (for LVH)



3. Special Tests (if secondary HTN suspected)


Renal Doppler


Plasma aldosterone–renin ratio


Thyroid function tests


24-hour urinary catecholamines


Cortisol testing


Sleep study (OSA)




  • Treatment of Hypertension


Management includes lifestyle changes, drug therapy, and regular follow-up.


1. Lifestyle Modifications


These are essential for all patients, regardless of BP level.


Weight reduction (most impactful)


Regular aerobic exercise


Low-sodium diet (<2 g/day)


DASH diet (fruits, vegetables, low-fat dairy)


Limit alcohol


Quit smoking


Stress management



2. Pharmacologic Therapy


First-Line Drugs


1. ACE Inhibitors



2. Angiotensin Receptor Blockers (ARBs)



3. Calcium Channel Blockers (CCBs)



4. Thiazide Diuretics




These are supported by large outcome trials for reducing:


Stroke


Heart failure


MI


CKD progression



When to Start Medication


BP ≥140/90 in general population


BP ≥130/80 in:


Diabetes


CKD


High CV risk




Second-Line / Add-On Drugs


Beta blockers – useful post-MI, HF, arrhythmia


Aldosterone antagonists – resistant HTN


Alpha blockers – BPH


Vasodilators – hydralazine, minoxidil



Combination Therapy


Often needed when:


Stage 2 hypertension


BP >20/10 mmHg above target


Hypertensive Emergencies


A medical emergency where severely elevated BP is accompanied by acute organ damage.


Examples of Organ Damage are:


Hypertensive encephalopathy


Stroke


Acute LV failure


Aortic dissection


Acute kidney injury


Myocardial ischemia



Management


Admit to ICU



IV medications:


Nicardipine


Labetalol


Nitroprusside (rare now)



Reduce mean arterial pressure by ≤25% in first hour


Avoid rapid or excessive lowering




Long-Term Management


Regular BP monitoring


Annual kidney function tests


Lifestyle reinforcement


Ensure medication adherence


Screen for complications periodically (eyes, ECG, urine protein)




Target BP Goals:


<130/80 mmHg → most patients


Elderly >65 years: SBP 130–139 mmHg (individualized)


Diabetes or CKD: <130/80 mmHg




Conclusion


Hypertension is a chronic but highly manageable disease. Early diagnosis, lifestyle modification, evidence-based pharmacotherapy, and consistent follow-up greatly reduce the risk of cardiovascular and renal complications. Medical students should understand the mechanisms, evaluation protocol, and management strategies to ensure optimal patient care.


Alzheimer’s Disease: Causes, Symptoms, Diagnosis and Management

Alzheimer’s Disease: Causes, Symptoms, Diagnosis, and Management What is Alzheimer’s disease? Alzheimer’s disease (AD) is a progressive neur...