diff --git a/app/health/family-invite.tsx b/app/health/family-invite.tsx
index 618df1d..de1d88d 100644
--- a/app/health/family-invite.tsx
+++ b/app/health/family-invite.tsx
@@ -1,7 +1,6 @@
 import { HeaderBar } from '@/components/ui/HeaderBar';
 import { useAppDispatch, useAppSelector } from '@/hooks/redux';
 import {
-  createFamilyGroup,
   fetchFamilyGroup,
   generateInviteCode,
   selectFamilyGroup,
@@ -13,16 +12,16 @@ import { Ionicons } from '@expo/vector-icons';
 import { LinearGradient } from 'expo-linear-gradient';
 import { Stack } from 'expo-router';
 import React, { useEffect, useState } from 'react';
-import { 
-  ActivityIndicator, 
-  Alert, 
-  Modal, 
-  ScrollView, 
-  Share, 
-  StyleSheet, 
-  Text, 
-  TouchableOpacity, 
-  View 
+import {
+  ActivityIndicator,
+  Alert,
+  Modal,
+  ScrollView,
+  Share,
+  StyleSheet,
+  Text,
+  TouchableOpacity,
+  View
 } from 'react-native';
 import { useSafeAreaInsets } from 'react-native-safe-area-context';
 
@@ -47,11 +46,6 @@ export default function FamilyInviteScreen() {
   // 处理邀请按钮点击
   const handleInvite = async () => {
     try {
-      // 如果没有家庭组，先创建一个
-      if (!familyGroup) {
-        await dispatch(createFamilyGroup('我的家庭')).unwrap();
-      }
-      
       // 生成邀请码
       await dispatch(generateInviteCode(24)).unwrap();
       
diff --git a/app/health/profile.tsx b/app/health/profile.tsx
index d5fe6b3..ec812b6 100644
--- a/app/health/profile.tsx
+++ b/app/health/profile.tsx
@@ -3,20 +3,29 @@ import { BasicInfoTab } from '@/components/health/tabs/BasicInfoTab';
 import { CheckupRecordsTab } from '@/components/health/tabs/CheckupRecordsTab';
 import { HealthHistoryTab } from '@/components/health/tabs/HealthHistoryTab';
 import { MedicalRecordsTab } from '@/components/health/tabs/MedicalRecordsTab';
+import { ConfirmationSheet } from '@/components/ui/ConfirmationSheet';
 import { HeaderBar } from '@/components/ui/HeaderBar';
 import { Colors } from '@/constants/Colors';
 import { ROUTES } from '@/constants/Routes';
-import { useAppSelector } from '@/hooks/redux';
+import { useAppDispatch, useAppSelector } from '@/hooks/redux';
+import { useAuthGuard } from '@/hooks/useAuthGuard';
 import { useColorScheme } from '@/hooks/useColorScheme';
 import { useI18n } from '@/hooks/useI18n';
+import {
+  fetchFamilyGroup,
+  joinFamilyGroup,
+  selectFamilyGroup,
+} from '@/store/familyHealthSlice';
 import { selectHealthHistoryProgress } from '@/store/healthSlice';
 import { DEFAULT_MEMBER_NAME } from '@/store/userSlice';
+import { Toast } from '@/utils/toast.utils';
 import { Ionicons } from '@expo/vector-icons';
+import { GlassView, isLiquidGlassAvailable } from 'expo-glass-effect';
 import { Image } from 'expo-image';
 import { LinearGradient } from 'expo-linear-gradient';
 import { Stack, useRouter } from 'expo-router';
-import React, { useMemo, useState } from 'react';
-import { ScrollView, StyleSheet, Text, TouchableOpacity, View } from 'react-native';
+import React, { useCallback, useEffect, useMemo, useState } from 'react';
+import { ScrollView, StyleSheet, Text, TextInput, TouchableOpacity, View } from 'react-native';
 import { useSafeAreaInsets } from 'react-native-safe-area-context';
 
 export default function HealthProfileScreen() {
@@ -25,8 +34,19 @@ export default function HealthProfileScreen() {
   const theme = (useColorScheme() ?? 'light') as 'light' | 'dark';
   const colorTokens = Colors[theme];
   const { t } = useI18n();
+  const dispatch = useAppDispatch();
+  const { ensureLoggedIn } = useAuthGuard();
+  const glassAvailable = isLiquidGlassAvailable();
   
   const [activeTab, setActiveTab] = useState(0);
+  const [joinModalVisible, setJoinModalVisible] = useState(false);
+  const [inviteCodeInput, setInviteCodeInput] = useState('');
+  const [relationshipInput, setRelationshipInput] = useState('');
+  const [isJoining, setIsJoining] = useState(false);
+  const [joinError, setJoinError] = useState<string | null>(null);
+  
+  // Redux state
+  const familyGroup = useAppSelector(selectFamilyGroup);
   
   // Mock user data - in a real app this would come from Redux/Context
   const userProfile = useAppSelector((state) => state.user.profile);
@@ -59,6 +79,61 @@ export default function HealthProfileScreen() {
     return Math.round((filledCount / totalFields) * 100);
   }, [userProfile.height, userProfile.weight, userProfile.waistCircumference]);
 
+  // 初始化获取家庭组信息
+  useEffect(() => {
+    dispatch(fetchFamilyGroup());
+  }, [dispatch]);
+
+  // 重置弹窗状态
+  useEffect(() => {
+    if (!joinModalVisible) {
+      setInviteCodeInput('');
+      setRelationshipInput('');
+      setJoinError(null);
+    }
+  }, [joinModalVisible]);
+
+  // 打开加入弹窗
+  const handleOpenJoin = useCallback(async () => {
+    const ok = await ensureLoggedIn();
+    if (!ok) return;
+    setJoinModalVisible(true);
+  }, [ensureLoggedIn]);
+
+  // 提交加入家庭组
+  const handleSubmitJoin = useCallback(async () => {
+    if (isJoining) return;
+    const ok = await ensureLoggedIn();
+    if (!ok) return;
+    
+    const code = inviteCodeInput.trim().toUpperCase();
+    const relationship = relationshipInput.trim();
+    
+    if (!code) {
+      setJoinError('请输入邀请码');
+      return;
+    }
+    if (!relationship) {
+      setJoinError('请输入与创建者的关系');
+      return;
+    }
+    
+    setIsJoining(true);
+    setJoinError(null);
+    
+    try {
+      await dispatch(joinFamilyGroup({ inviteCode: code, relationship })).unwrap();
+      await dispatch(fetchFamilyGroup());
+      setJoinModalVisible(false);
+      Toast.success('成功加入家庭组');
+    } catch (error) {
+      const message = typeof error === 'string' ? error : '加入失败，请检查邀请码是否正确';
+      setJoinError(message);
+    } finally {
+      setIsJoining(false);
+    }
+  }, [dispatch, ensureLoggedIn, inviteCodeInput, isJoining, relationshipInput]);
+
   const gradientColors: [string, string] =
     theme === 'dark'
       ? ['#1f2230', '#10131e']
@@ -107,6 +182,25 @@ export default function HealthProfileScreen() {
         transparent
         right={
           <View style={{ flexDirection: 'row', alignItems: 'center' }}>
+            {/* 加入家庭组按钮 - 仅在未加入家庭组时显示 */}
+            {!familyGroup && (
+              <TouchableOpacity activeOpacity={0.85} onPress={handleOpenJoin} style={{ marginRight: 10 }}>
+                {glassAvailable ? (
+                  <GlassView
+                    style={styles.joinButtonGlass}
+                    glassEffectStyle="regular"
+                    tintColor="rgba(255,255,255,0.18)"
+                    isInteractive
+                  >
+                    <Text style={styles.joinButtonLabel}>加入</Text>
+                  </GlassView>
+                ) : (
+                  <View style={[styles.joinButtonGlass, styles.joinButtonFallback]}>
+                    <Text style={[styles.joinButtonLabel, { color: colorTokens.text }]}>加入</Text>
+                  </View>
+                )}
+              </TouchableOpacity>
+            )}
             <TouchableOpacity style={{ marginRight: 12 }}>
               <Ionicons name="settings-outline" size={22} color="#1F2937" />
             </TouchableOpacity>
@@ -125,7 +219,10 @@ export default function HealthProfileScreen() {
                <Image source={{ uri: avatarUrl }} style={styles.miniAvatar} />
                <Text style={styles.miniAvatarName}>{displayName}</Text>
              </View>
-             <TouchableOpacity style={styles.addButton}>
+             <TouchableOpacity 
+               style={styles.addButton}
+               onPress={() => router.push(ROUTES.HEALTH_FAMILY_INVITE)}
+             >
                <Ionicons name="add" size={16} color="#6B7280" />
              </TouchableOpacity>
           </View>
@@ -205,7 +302,44 @@ export default function HealthProfileScreen() {
 
       </ScrollView>
       
-      {/* Privacy Warning Footer - Removed as requested */}
+      {/* 加入家庭组弹窗 */}
+      <ConfirmationSheet
+        visible={joinModalVisible}
+        onClose={() => setJoinModalVisible(false)}
+        onConfirm={handleSubmitJoin}
+        title="加入家庭组"
+        description="输入家人分享的邀请码，加入家庭健康管理"
+        confirmText={isJoining ? '加入中...' : '加入'}
+        cancelText="取消"
+        loading={isJoining}
+        content={
+          <View style={styles.modalInputWrapper}>
+            <TextInput
+              style={styles.modalInput}
+              placeholder="请输入邀请码"
+              placeholderTextColor="#9ca3af"
+              value={inviteCodeInput}
+              onChangeText={(text) => setInviteCodeInput(text.toUpperCase())}
+              autoCapitalize="characters"
+              autoCorrect={false}
+              keyboardType="default"
+              maxLength={12}
+            />
+            <TextInput
+              style={[styles.modalInput, { marginTop: 12 }]}
+              placeholder="与创建者的关系（如：配偶、父母、子女）"
+              placeholderTextColor="#9ca3af"
+              value={relationshipInput}
+              onChangeText={setRelationshipInput}
+              autoCorrect={false}
+              maxLength={20}
+            />
+            {joinError && joinModalVisible ? (
+              <Text style={styles.modalError}>{joinError}</Text>
+            ) : null}
+          </View>
+        }
+      />
     </View>
   );
 }
@@ -339,5 +473,45 @@ const styles = StyleSheet.create({
     textAlign: 'center',
     lineHeight: 18,
   },
-
+  joinButtonGlass: {
+    paddingHorizontal: 14,
+    paddingVertical: 8,
+    borderRadius: 16,
+    minWidth: 60,
+    alignItems: 'center',
+    justifyContent: 'center',
+    borderWidth: StyleSheet.hairlineWidth,
+    borderColor: 'rgba(255,255,255,0.45)',
+  },
+  joinButtonLabel: {
+    fontSize: 12,
+    fontWeight: '700',
+    color: '#0f1528',
+    letterSpacing: 0.5,
+    fontFamily: 'AliBold',
+  },
+  joinButtonFallback: {
+    backgroundColor: 'rgba(255,255,255,0.7)',
+  },
+  modalInputWrapper: {
+    borderRadius: 14,
+    borderWidth: 1,
+    borderColor: '#e5e7eb',
+    backgroundColor: '#f8fafc',
+    paddingHorizontal: 12,
+    paddingVertical: 10,
+    gap: 6,
+  },
+  modalInput: {
+    paddingVertical: 12,
+    fontSize: 16,
+    fontWeight: '600',
+    letterSpacing: 0.5,
+    color: '#0f1528',
+  },
+  modalError: {
+    marginTop: 10,
+    fontSize: 12,
+    color: '#ef4444',
+  },
 });
diff --git a/app/weight-records.tsx b/app/weight-records.tsx
index 836c89e..0eaaeb5 100644
--- a/app/weight-records.tsx
+++ b/app/weight-records.tsx
@@ -265,9 +265,9 @@ export default function WeightRecordsPage() {
                 <Text style={styles.mainStatUnit}>kg</Text>
               </View>
               <View style={styles.totalLossTag}>
-                <Ionicons name={totalWeightLoss <= 0 ? "trending-down" : "trending-up"} size={16} color="#ffffff" />
+                <Ionicons name={totalWeightLoss > 0 ? "trending-down" : "trending-up"} size={16} color="#ffffff" />
                 <Text style={styles.totalLossText}>
-                  {totalWeightLoss > 0 ? '+' : ''}{totalWeightLoss.toFixed(1)} kg
+                  {totalWeightLoss > 0 ? '-' : totalWeightLoss < 0 ? '+' : ''}{Math.abs(totalWeightLoss).toFixed(1)} kg
                 </Text>
               </View>
             </View>
diff --git a/services/healthProfile.ts b/services/healthProfile.ts
index 5848859..7cadca5 100644
--- a/services/healthProfile.ts
+++ b/services/healthProfile.ts
@@ -172,14 +172,6 @@ export async function getFamilyGroup(): Promise<FamilyGroup | null> {
   }
 }
 
-/**
- * 创建家庭组
- * @param name 家庭组名称
- */
-export async function createFamilyGroup(name: string): Promise<FamilyGroup> {
-  return api.post<FamilyGroup>('/api/health-profiles/family/group', { name });
-}
-
 /**
  * 生成家庭组邀请码
  * @param expiresInHours 过期时间（小时），默认24小时
diff --git a/store/familyHealthSlice.ts b/store/familyHealthSlice.ts
index 2fad17e..c14d481 100644
--- a/store/familyHealthSlice.ts
+++ b/store/familyHealthSlice.ts
@@ -2,8 +2,8 @@
  * 家庭健康管理 Redux Slice
  */
 
-import { createAsyncThunk, createSlice, PayloadAction } from '@reduxjs/toolkit';
 import * as healthProfileApi from '@/services/healthProfile';
+import { createAsyncThunk, createSlice } from '@reduxjs/toolkit';
 import { RootState } from './index';
 
 // ==================== State 类型定义 ====================
@@ -56,21 +56,6 @@ export const fetchFamilyGroup = createAsyncThunk(
   }
 );
 
-/**
- * 创建家庭组
- */
-export const createFamilyGroup = createAsyncThunk(
-  'familyHealth/createGroup',
-  async (name: string, { rejectWithValue }) => {
-    try {
-      const data = await healthProfileApi.createFamilyGroup(name);
-      return data;
-    } catch (err: any) {
-      return rejectWithValue(err?.message ?? '创建家庭组失败');
-    }
-  }
-);
-
 /**
  * 生成邀请码
  */
@@ -208,20 +193,6 @@ const familyHealthSlice = createSlice({
         state.error = action.payload as string;
       })
       
-      // 创建家庭组
-      .addCase(createFamilyGroup.pending, (state) => {
-        state.loading = true;
-        state.error = null;
-      })
-      .addCase(createFamilyGroup.fulfilled, (state, action) => {
-        state.loading = false;
-        state.familyGroup = action.payload;
-      })
-      .addCase(createFamilyGroup.rejected, (state, action) => {
-        state.loading = false;
-        state.error = action.payload as string;
-      })
-      
       // 生成邀请码
       .addCase(generateInviteCode.pending, (state) => {
         state.inviteLoading = true;