Thyroid For Dummies

Alan L. Rubin, MD has over thirty years' experience treating thyroid conditions and is the co-author of Diabetes For Dummies. Dr. Sarah Brewer is the co-author of Arthritis For Dummies, a health writer and broadcaster, and a former Health Journalist of the Year.

Introduction 1

About This Book 2

Conventions Used in This Book 2

What You Don’t Have to Read 2

Assumptions 3

How This Book Is Organised 3

Part I: Understanding Your Thyroid 3

Part II: Treating Thyroid Problems 3

Part III: Managing Your Thyroid 3

Part IV: Considering Special Aspects of Thyroid Health 4

Part V: The Part of Tens 4

Part VI: Appendices 4

Icons Used in This Book 4

Where to Go from Here 5

Part I: Understanding the Thyroid 7

Chapter 1: Bigging It Up: The Huge Role of a Little Gland 9

Discovering the Extent of the Problem 10

Identifying an Unhappy Thyroid 11

Recognising Who’s at Risk 11

Realising the Importance of a Healthy Thyroid 12

Treating What Ails You 12

Understanding the Consequences of Delaying Treatment 14

Giving Your Thyroid a Hand: Healthy Lifestyle Choices 14

Paying Special Attention: Pregnant Women, Children, and Older People 15

Staying Informed 16

Chapter 2: Feeling Fragile: The Emotional Effects of Thyroid Problems 17

Exploring How an Underactive Thyroid Slows Your Thoughts 18

Seeing How an Overactive Thyroid Can Trigger Anxiety 19

Fighting Depression 20

Finding out if your thyroid is causing depression 21

Using thyroid hormone to treat depression 22

Chapter 3: Discovering How Your Thyroid Works 25

Locating the Thyroid 26

Producing Thyroid Hormones 28

Identifying the importance of iodine 29

Regulating thyroid hormones 29

Moving thyroid hormones around 30

Understanding the Function of Thyroid Hormones 31

General functions 32

Specific functions 33

Chapter 4: Testing Your Thyroid 37

Checking Blood Levels of Thyroid Hormones 38

Total thyroxine 38

Resin T3 uptake 40

Free thyroxine index 40

Free thyroxine (FT4) 41

Free triiodothyronine (FT3) 42

Thyroid-stimulating hormone (TSH) 42

Taking Non-Hormonal Blood Tests 43

Thyroid autoantibodies 44

Serum thyroglobulin 45

Determining the Size, Shape, and Content of Your Thyroid 46

Radioactive iodine uptake and scan 46

Thyroid ultrasound 48

Fine needle aspiration biopsy (FNAB) 49

Part II: Treating Thyroid Problems 51

Chapter 5: Dealing with an Underactive Thyroid 53

Living with Autoimmune Thyroiditis 54

The extent of the problem 54

Symptoms of chronic thyroiditis 55

Approach to treatment 55

Identifying Hypothyroidism 56

Signs and symptoms of hypothyroidism 56

Confusing conditions 57

Pinpointing the Causes of Hypothyroidism 58

Removal of the thyroid 58

Absence of brain hormones 58

Foods that cause hypothyroidism 59

Drugs that cause hypothyroidism 59

Coexisting autoimmune diseases 60

Diagnosing Severe Hypothyroidism 61

Treating Hypothyroidism 61

Taking the right hormones 61

Getting the right amount 63

Testing hormone levels 64

Chapter 6: Taming an Overactive Thyroid 65

Picturing Hyperthyroidism 66

Listing the Signs and Symptoms of Hyperthyroidism 66

The body generally 67

The thyroid 67

The skin and hair 67

The heart 68

The nervous system and muscles 68

The reproductive system 68

The stomach and intestines 68

The urinary system 68

The eyes 69

Confirming a Diagnosis of Hyperthyroidism 69

Determining Whether Graves’ Disease Is the Culprit 70

Causes of Graves’ disease 70

Signs and symptoms specific to Graves’ disease 71

Recognising Other Causes of Hyperthyroidism 73

Choosing the Best Treatment for Graves’ Disease 74

Thyroid surgery 75

Radioactive iodine treatment 76

Antithyroid pills 77

Other helpful medications 79

Treating Other Causes of Hyperthyroidism 79

Surviving Thyroid Storm 80

Chapter 7: Getting the Low-Down on Thyroid Nodules 81

Discovering a Thyroid Nodule 82

Evaluating Cancer Risks 83

Securing a Diagnosis 83

The fine needle aspiration cytology 84

The thyroid ultrasound scan 85

Treating Cancerous Nodules 86

Dealing with Nodules That Are Non-Cancerous 86

Hot nodules 87

Benign cysts 87

Warm or cold nodules 87

Ignoring Small Nodules 87

Chapter 8: Coping with Thyroid Cancer 89

Determining What Causes Thyroid Cancer 90

Identifying the Types of Thyroid Cancer 91

Papillary thyroid cancer 92

Follicular thyroid cancer 93

Medullary thyroid cancer 93

Undifferentiated (anaplastic) thyroid cancer 95

Staging Thyroid Cancer 96

Treating Thyroid Cancer 97

Papillary thyroid cancer 98

Follicular thyroid cancer 99

Medullary thyroid cancer 99

Undifferentiated (anaplastic) thyroid cancer 100

Following Up Cancer Treatment 100

Chapter 9: Learning about Multinodular Goitres 101

Exploring How a Multinodular Goitre Grows Up 101

Choosing to Treat It or Ignore It 103

Making a Diagnosis 104

Treating a Multinodular Goitre 105

Part III: Managing Your Thyroid 107

Chapter 10: Taking Care with Drugs That Affect Your Thyroid 109

Revealing the Drug–Food–Thyroid Connection 109

Identifying the Effects of Specific Substances 112

Initiating or aggravating hypothyroidism 113

Creating false test results 117

Causing an increase in thyroid activity 118

Preventing Harmful Drug Interactions 119

Discovering Whether You’re at Risk 119

Chapter 11: Spotting Thyroid Infections and Inflammation 123

Putting a Face on Subacute Thyroiditis 123

Causes and effects 124

Laboratory findings 125

Treatment options 126

Coping with Postpartum and Silent Thyroiditis 127

Understanding the disease 127

Interpreting lab results 128

Getting treatment 128

Identifying Acute Thyroiditis 129

Describing the disease 129

Confirming the diagnosis with lab tests 130

Treating acute thyroiditis 130

Diagnosing a Rare Form of Thyroiditis 131

Chapter 12: Overcoming Iodine Deficiency Disease 133

Realising the Vastness of the Problem 134

Facing the Consequences of Iodine Lack 135

Pregnancy 135

Infancy 136

Childhood 136

Adulthood 136

Endemic Cretinism 137

Looking at the geographic distribution 138

Contributing factors 139

Goitre: The body’s defence 140

Neurologic cretinism 141

Myxoedematous cretinism 141

Managing the Problem of Iodine Deficiency 142

A sprinkle of salt 143

An injection of oil 144

A slice of bread or cup of water 145

Drawbacks of Iodisation 145

Chapter 13: Going In: Surgery on the Thyroid Gland 147

Deciding When Surgery Is Necessary 147

Talking Things Over 149

Preparing for Surgery 149

What Happens During Surgery 150

Surgical obstacles 151

Extent of surgery 152

Considering a New Approach 154

Possible Complications 155

Recuperating After the Operation 155

Chapter 14: Exciting New Approaches in Thyroid Treatment 157

Preventing Ill Effects of Large Doses of Iodine 157

Finding Out More about Hypothyroidism 158

Treating (or not treating) subclinical hypothyroidism 158

Finding the right dose of hormone 159

Determining the prevalence of hypothyroidism 160

Linking heart disease and hypothyroidism 160

Dealing with Hyperthyroidism 161

Measuring calcium levels 162

Controlling weight gain 162

Revolutionising thyroid surgery 163

Gathering clues to hyperthyroid eye disease 163

Treating Goitres and Nodules 164

Performing surgery after ethanol injections 164

Shrinking goitres 164

Developing New Approaches in Thyroid Cancer 165

Understanding the impact of radioiodine exposure 165

Blocking oestrogen slows tumour growth 166

Predicting thyroid cancer 166

Detecting residual thyroid cancer 166

Following up thyroid cancer treatment 167

Knowing what to expect from medullary thyroid cancer 168

Using recombinant TSH to treat thyroid cancer 169

Testing calcium levels after cancer surgery 170

Tackling Iodine Deficiency Disease 170

Recognising the importance of selenium 170

Using iodised oil for goitres 171

Increasing the intelligence of babies born to hypothyroid mothers 171

Chapter 15: Living with Thyroid Problems: Diet and Exercise 173

Guaranteeing Your Best Nutrition 173

Maintaining a Healthy Weight 174

Calculating your body mass index 175

Measuring your waist size 176

Losing excess weight 177

Selecting a variety of foods 177

Choosing your fats wisely 182

Checking out your cholesterol 182

Moderating your sugar intake 184

Sifting the salt 184

Drinking alcohol in moderation 185

Going Organic 186

Thinking about food safety 186

Clarifying the Thyroid–Weight Connection 187

Does my metabolism slow when I lose weight? 187

If I’m treated for hyperthyroidism, am I doomed to gain weight? 187

Considering Iodine in Your Diet 189

Getting enough iodine in a vegetarian diet 189

Exercising for Your Thyroid 190

Recognising the natural consequences of ageing 190

Working out with hypothyroidism 191

Exercising with hyperthyroidism 192

Meeting your minimal exercise needs 193

Introducing Leptin: The New Hormone on the Block 194

Understanding the functions of leptin 194

Interacting with thyroid hormone 195

Chapter 16: Helping Yourself: Herbs and Homeopathy 197

Finding a Reputable Practitioner 198

Digging into Medicinal Herbs 199

Bladderwrack 199

Bugleweed 200

Korean ginseng 200

Motherwort 200

Oats 201

Siberian ginseng 201

Turmeric 201

Valerian 201

Understanding Homeopathy 202

Discovering homeopathic remedies 202

Taking a remedy 203

Arsenicum album 203

Iodum 204

Belladonna 204

Natrum Mur 204

Part IV: Special Considerations in Thyroid Health 205

Chapter 17: Examining the Genetic Link to Thyroid Disease 207

Genetics for Beginners 207

A monk and his pea plants 208

Talk the talk 209

The great divide 209

Genes, chromosomes, and the traits they create 210

The secret lives of genes 211

Shall I form a liver or a brain? 213

The Origins of Genetic Thyroid Diseases 214

Inheriting a disease through a single gene 214

Inheriting a disease through multiple genes 216

Inheriting a chromosome abnormality 217

The Future of Managing Hereditary Thyroid Disease 218

Genetic engineering 218

The ethics of germline gene therapy 219

Chapter 18: Controlling Thyroid Disease during Pregnancy 221

Looking at Normal Thyroid during Pregnancy 222

Pregnancy and Hypothyroidism 223

Decreased fertility 223

Iodine deficiency 224

Autoimmune hypothyroidism 224

Hyperthyroidism in Pregnancy 225

Postpartum Graves’ disease 229

Gestational transient thyrotoxicosis 229

Hydatidiform mole and choriocarcinoma 231

Finding New Thyroid Nodules during Pregnancy 231

Chapter 19: Developing Thyroid Conditions in Childhood 233

Understanding the Onset of Thyroid Function 233

Screening the Newborn 235

Coping with Hypothyroidism in Children 236

Transient congenital hypothyroidism 237

Congenital hypothyroidism 237

Acquired hypothyroidism 239

Dealing with Hyperthyroidism in Children 241

Signs and symptoms 241

Laboratory confirmation 243

Treatment 243

Diagnosing Goitres in Children 245

Linking Nodules and Cancer in Children 245

Chapter 20: Maturing: Thyroid Disease in Later Life 247

Assessing the Extent of the Problem 248

Understanding Sources of Confusion in Diagnosis 249

Acknowledging other diseases 249

Taking medications 250

Discovering Hypothyroidism in Older People 250

Deciphering signs and symptoms 251

Getting laboratory confirmation 252

Trying thyroid hormone for subclinical patients 252

Taking treatment slowly 253

Managing Hyperthyroidism in Older People 253

Sorting through confusing signs and symptoms 254

Securing a diagnosis 255

Checking Out Thyroid Nodules in Older People 256

Part V: The Part of Tens 257

Chapter 21: Ten Myths about Thyroid Health 259

I’m Hypothyroid, So I Can’t Lose Weight 259

I’m Hyperthyroid, So I Can’t Gain Weight 260

Breastfeeding and Antithyroid Pills Don’t Mix 261

Brand Name Thyroid Hormone Pills Are Best 261

I Have to Take Thyroid Medication for Life 262

Natural Thyroid Hormones Are Better Than Synthetic Hormones 263

Thyroid Disease Is Catching 264

Iodine Deficiency Is a Medical Problem 264

The Higher My Autoantibody Levels, the Worse My Thyroid Disease 265

Clinical Symptoms Are More Reliable Than Blood Tests 266

Chapter 22: Ten Ways to Maximise Thyroid Health 269

Screening at Appropriate Intervals 270

Checking Thyroid Function As Your Body Changes 270

Performing a ‘Neck Check’ 271

Getting Enough Iodine to Satisfy Your Thyroid 272

Stopping Thyroid Medication, If Possible 272

Using Both Types of Thyroid Hormone 272

Preventing the Regrowth of Thyroid Cancer 273

Anticipating Drug Interactions 274

Protecting Your Thyroid from Radiation 275

Keeping Up-to-Date with Thyroid Discoveries 275

Part VI: Appendixes 277

Appendix A: Glossary of Key Terms 279

Appendix B: Sources of More Information 283

Index 285